know

Old Breton: cnou

Middle Breton: cnou

Breton: kraou, kraoñ

Cornish: know

Middle Welsh: kneu

Welsh: cnau

From Proto-Celtic *knuwes, plural of *knūs.


dar

Old Breton: dar

Breton: dar

Old Cornish: dar

Cornish: dar

Middle Welsh: dar

Welsh: dâr

From Proto-Celtic *daru, from Proto-Indo-European *dóru.


son

Breton: son, soun

Middle Cornish: son

Cornish: son

Middle Welsh: son, sson

Welsh: sôn

Borrowed from Latin sonus. Parallel borrowing with Old Irish son (“sound”).


tan

Old Breton: tan

Middle Breton: tan

Breton: tan

Old Cornish: tan

Middle Cornish: tan

Cornish: tan

Middle Welsh: tan

Welsh: tân


ben

Old Breton: ban- (in ban-leu, ban-doiuis)

Middle Breton: e-ben

Breton: eben

Old Cornish: benen

Cornish: ben, benyn

Old Welsh: ben

Welsh: benyw, menyw


bran

Middle Breton: bran

Breton: bran

Middle Cornish: bran

Cornish: bran

Middle Welsh: bran

Welsh: brân f


angel

Middle Breton: ael, el

Breton: ael

Old Cornish: ail

Middle Cornish: êl, eyl, eal

Cornish: el

Middle Welsh: angel

Welsh: angel

Borrowed from Latin angelus. Parallel borrowing with Old Irish aingel.


ber

Middle Breton: ber

Breton: ber

Old Cornish: ber

Cornish: ber

Middle Welsh: ber

Welsh: bêr

From Proto-Celtic *beru, from Proto-Indo-European *gʷéru.


dig

Middle Welsh: dic

Welsh: dig


mer

Breton: mel (“marrow”)

Cornish: mer

Welsh: mêr

From Proto-Celtic *smerus, from Proto-Indo-European *smérus.


ar

Middle Welsh: ar

From Proto-Celtic *aros. Cognate with Old Irish ar.


aber

desc

Old Breton: aperou pl (possibly borrowed from Old Welsh)

Breton: aber
→ French: aber

Old Cornish: aber

Old Welsh: aper

Middle Welsh: aber

Welsh: aber


per

Middle Breton: per

Breton: per

Old Cornish: *per (in compound)

Middle Cornish: per

Cornish: per

Middle Welsh: per

Welsh: pêr

Borrowed from Latin pira, plural of pirum. In Vulgar Latin pira was reanalysed as a feminine singular (*pira), but the plural number of *per suggests that this is not the form that underlies the borrowing into Brythonic.


bos

Middle Breton: boz

Breton: boz

Old Welsh: bos

Middle Welsh: bos

Welsh: bos


nei

Old Breton: ny

Middle Breton: ni

Breton: ni

Cornish: noi, noy

Old Welsh: nei

Welsh: nai


fin

q

or borrowed from Middle French <i class="Latn mention" lang="frm">fin</i> (“end”)

Middle Breton: fin (“end”) (or borrowed from Middle French fin (“end”))

Breton: fin (“end”)

Middle Cornish: fin, fen

Cornish: fin

Old Welsh: fin

Middle Welsh: ffin

Welsh: ffin

Borrowed from Latin fīnis (“end, limit”). Parallel borrowing with Middle Irish fín (“end”).


din

Old Breton: din

Breton: din

Cornish: din

Old Welsh: din

Middle Welsh: din

Welsh: din

From Proto-Celtic *dūnom (“fort, rampart”).


fer

Old Cornish: fer

Middle Welsh: ffer

Welsh: ffêr


pal

Breton: pal, bal

Cornish: pal

Middle Welsh: pal

Welsh: pâl

Uncertain; possibly either borrowed from Latin pāla (“shovel, spade”), or inherited from Proto-Celtic *kʷalos, from Proto-Indo-European *kʷel(h₁)- (“to turn”).


brad

Old Breton: brat

Middle Breton: barat

Breton: barad

Middle Cornish: bras

Cornish: bras

Middle Welsh: brat, brad

Welsh: brad


tad

Middle Breton: tat

Breton: tad (“father”), tata (“dad”)

Old Cornish: tat (c. 1250)

Cornish: tas, tat

Middle Welsh: tad

Welsh: tad (“father”), dada (“dad”)

From Proto-Celtic *tatos, of nursery/expressive origin. Compare Latin tata.

onomatopoeic

expressive


mox

Old Breton: moch

Middle Breton: moch

Breton: moc'h

Middle Cornish: mogh

Cornish: mogh

Old Welsh: moch

Middle Welsh: moch

Welsh: moch


ki

Middle Breton: ci, qui

Breton: ki

Old Cornish: ci

Cornish: ki, kei

Middle Welsh: ci, ki

Welsh: ci

From Proto-Celtic *kū, from Proto-Indo-European *ḱwṓ.


eb

Old Breton: eb

desc

Breton: keneb (“mare in foal”), ebeul (“colt, foal”)

Old Welsh: eb

Middle Welsh: ep, ebawl (“colt, foal”)

Welsh: cyfeb (“mare in foal”), ebol (“colt, foal”), ebran (“fodder, stover”)

From earlier *epos, from Proto-Celtic *ekʷos.


mil

Middle Breton: mil

Breton: mil

Old Cornish: mil

Middle Cornish: mil, myl

Cornish: mil

Middle Welsh: mil

Welsh: mil


awr

Breton: aour

Old Cornish: our

Cornish: owr

Old Welsh: our

Welsh: awr

Middle Welsh: eur (probably < Latin aureus)

Welsh: aur

Borrowed from Latin aurum (“gold”). Parallel borrowing with Old Irish ór (“gold”).


stor

Welsh: ystor

Borrowed from Latin storāx, styrax (“storax tree, resin of the storax tree”).


pont

Middle Breton: pont

Breton: pont

Old Cornish: pons

Middle Cornish: pons

Cornish: pons

Cumbric: *pont

⇒ Cumbric: *Pen(n)pont

→ English: Penpont

Old Welsh: pont

Middle Welsh: pont

Welsh: pont

Borrowed from an oblique case of Latin pōns.


mor

Old Breton: mor

Middle Breton: mor

Breton: mor

Old Cornish: mor

Middle Cornish: mor

Cornish: mor

Middle Welsh: mor

Welsh: môr

From Proto-Celtic *mori, from Proto-Indo-European *móri.


gal

Old Breton: gal


bann

Middle Breton: ban

Breton: bann

Cornish: ban

Middle Welsh: bann

Welsh: ban


dün

Old Breton: don, den

Middle Breton: den

Breton: den

Old Cornish: den

Cornish: den

Middle Welsh: dyn

Welsh: dyn


með

Middle Breton: mez

Breton: mez

Cornish: medh

Middle Welsh: medd

Welsh: medd

From Proto-Celtic *medu, from Proto-Indo-European *médʰu.


tir

Middle Breton: tir

Breton: tir

Old Cornish: tir
Cornish: tir

desctree

Old Welsh: tir
Middle Welsh: tir
Welsh: tir

Either from s-stem Proto-Celtic *tīros, direct cognate with Old Irish tír, or n-stem Proto-Celtic *tīryū, singular to n-stem plural *tirjon.


gen

Old Breton: gen

Middle Breton: guen

Breton: gen

Old Cornish: genau

Cornish: gen

Middle Welsh: gen

Welsh: gên

From Proto-Celtic *genus, from Proto-Indo-European *ǵénus.


benn

Middle Welsh: benn


ster

Old Breton: *ster

Middle Breton: ster

Breton: ster

Old Cornish: *ster

Middle Cornish: ster, steyr

Cornish: ster

Old Welsh: *ser

Middle Welsh: ser, syr

Welsh: sêr

From Proto-Celtic *sterās, plural of *sterā, from Proto-Indo-European *h₂stḗr. The Proto-Celtic nominative singular and plural would have become homophones in Proto-Brythonic, and in this case the plural was generalized.


dol

Breton: *dol (found in placenames)

Middle Welsh: dol

Welsh: dôl

⇒ Welsh: Blaenydhôl

⇒ Welsh: Dolgarrog

Cornish: *dol (found in placenames)

⇒ Cornish: Dollywhiddens

⇒ Cornish: Godolphin

Uncertain; possibly inherited from Proto-Celtic *dolā, cognate with Proto-Germanic *dalą, *dōljō (“valley”), though perhaps instead borrowed from Germanic, compare Irish dail (“field, meadow”), itself borrowed from Old Norse dalr (“meadow, dale”).


kar

Middle Breton: car

Breton: kar

Old Cornish: car

Cornish: kar

Middle Welsh: car

Welsh: câr


kas

Middle Breton: cas

Breton: kas

Cornish: kas

Old Welsh: cas

Middle Welsh: cas

Welsh: cas


tann

Breton: tann

Cornish: tannen


gwen

Cornish: gwen

Welsh: gwên


korf

Middle Breton: corff, corf, corph

Breton: korf

Middle Cornish: corf

Cornish: korf

Middle Welsh: corf, corff, corph

Welsh: corff

Borrowed from Latin corpus, cognate with Proto-Brythonic *krɨβ̃ (“strong”). Parallel borrowing with Old Irish corp (“body”).


krank

Middle Breton: cranq, crancq

Breton: krank

Middle Welsh: cranc

Welsh: cranc

Likely borrowed from Late Latin crancus (compare Catalan cranc, Occitan cranc; Italian granchio, from *cranculus), a metathetic form of cancer (“crab”). Doublet of *kankr, whence Old Cornish cancher (“crab”).


glin

Breton: glin

Cornish: glin

Welsh: glin

From Proto-Celtic *glūnos. Cognate with Old Irish glún.


skol

Breton: skol

Old Cornish: scol

Cornish: scol

Middle Welsh: yscol

Welsh: ysgol

Borrowed from Latin schola (“school”). Parallel borrowing with Old Irish scol (“school”).


kad

Breton: kad

Cornish: kas

Welsh: cad

From Proto-Celtic *katus, from Proto-Indo-European *kéh₃tus.


aren

Middle Welsh: arenn

Welsh: aren

From pre-Proto-Brythonic *arenā, rebuilt ā-stem from Proto-Celtic *arenos, genitive singular of *ārū (“kidney”).


korr

Middle Breton: corr

Breton: korr

Old Cornish: cor

Cornish: korr

Middle Welsh: corr

Welsh: cor

From Proto-Celtic *korros, probably from Proto-Indo-European *(s)kert- (“short”), from *(s)ker- (“to cut”).
See also Scots short, schort (“short”), Old High German scurz (“short”), Middle High German schurz, Old Norse skorta (“to lack”), Danish skorte, Albanian shkurt (“short, brief”), English short.


gwlad

Breton: glad

Old Cornish: gulat

Cornish: gulas, gwlas

Old Welsh: gulat

Middle Welsh: gwlad

Welsh: gwlad


komm

Breton: komm (“river-bed”)

Middle Welsh: cwm

Welsh: cwm

→ English: cwm

→ Old English: cumb (partially)

English: combe, coomb

From Proto-Celtic *kumbā. Cognate with Gaulish *kumba.


gwaladr

Welsh: gwaladr


penn

Old Breton: penn, pen

Middle Breton: penn, pen

Breton: penn

Old Cornish: pen

Middle Cornish: pen

Cornish: penn, pedn

Old Welsh: penn

Middle Welsh: penn

Welsh: pen

Cumbric: pen


mab

Old Breton: map, mab

Middle Breton: mab

Breton: mab

Old Cornish: mab, map

Cornish: mab

Old Welsh: map

Middle Welsh: map

Welsh: mab

From earlier *mapos, from Proto-Celtic *makʷos.


mamm

Middle Breton: mamm

Breton: mamm

Old Cornish: mam

Middle Cornish: mam

Cornish: mamm

Middle Welsh: mam

Welsh: mam

From Proto-Celtic *mammā. Compare Latin mamma.


gwin

Breton: gwin

Cornish: gwin, gwyn

Welsh: gwin

From Proto-Celtic *wīnom, from Latin vīnum.


selsig

Middle Breton: silsicq, silsig

Breton: silzig

Old Welsh: selsic

Middle Welsh: selsic

Welsh: selsig

→ Cornish: selsik

Borrowed from Late Latin (farta) salsīcia.


sux

Middle Breton: souch

Breton: soc’h

Welsh: swch

From Proto-Celtic *sukkos (“pig; snout (of a pig); plowshare”), under the influence of, if not borrowed from, Vulgar Latin *soccus (“plowshare”) (whence Old French soc, soket), itself borrowed from Celtic. Doublet of *hux (“pig”).


kurr

Cornish: cor

Welsh: cwr

From Proto-Celtic *kurros (“pointed, angled”). Cognate with Middle Irish corr.


tarw

Old Breton: taruu

Middle Breton: taru

Breton: tarw, tarv

Old Cornish: tarow

Cornish: tarow

Middle Welsh: tarw

Welsh: tarw

From Proto-Celtic *tarwos, from Proto-Indo-European *táwros.


llew

Breton: *leu

⇒ Breton: leugui (“lion”)

Cornish: lew

Middle Welsh: llew

Welsh: llew

Borrowed from Latin leō. Parallel borrowing with Old Irish léo (“lion”).


anadl

Middle Breton: alazn, azlan

Breton: alan

Middle Cornish: anel

Cornish: anal

Middle Welsh: anadyl, anadl

Welsh: anadl

From Proto-Celtic *anatlā, from Proto-Indo-European *h₂enh₁- (“to breathe”). Cognate with Old Irish anál.


awel

Old Breton: avelou

Middle Breton: avel, auel (“wind”)

Breton: awel

Old Cornish: auhel

Cornish: awel

Middle Welsh: awel

Welsh: awel


karn

Old Breton: carn

Middle Breton: (Pen) karn

Breton: karn

Old Cornish: carn

Cornish: karn

desc

Middle Welsh: carn, carnau, cernydd, cerni

Welsh: carn


dant

Old Breton: dant

Middle Breton: dant

Breton: dant

Old Cornish: dans

Cornish: dans

Middle Welsh: dant

Welsh: dant

From Proto-Celtic *dant, from Proto-Indo-European *h₃dónts.


karant

Welsh: carant


kastell

Breton: kastell

Cornish: kastel

Middle Welsh: castell

Welsh: castell

Borrowed from Latin castellum. Parallel borrowing with Old Irish caisel (“ringfort”).


glaw

Breton: glav

Cornish: glaw

Welsh: glaw

Of unclear origin. Jones tentatively connects the term to Sanskrit जल (jala, “water”), itself perhaps related to गलति (galati, “to drip”) and German quellen (“to well up”). This is semantically appealing; however, Proto-Brythonic *g should yield a *ǵʰ in Proto-Indo-European, while the suggested cognates yield a *gʷ.


pobl

Old Breton: *popl (in compound)

Middle Breton: pobl

Breton: pobl

Old Cornish: popel

Middle Cornish: pobel, pobyl

Cornish: pobel

Middle Welsh: pobyl

Welsh: pobl

desctree

→ Old Irish: popul
Middle Irish: popul
Irish: pobal
Manx: pobble
Scottish Gaelic: poball

Borrowed from Vulgar Latin poplus, from Latin populus. Parallel borrowing with Old Irish popul (“people”).


bronn

Old Breton: bronn

Middle Breton: bronn

Breton: bronn

Cornish: bronn

Middle Welsh: bron

From pre-Proto-Brythonic *brusnā, rebuilt ā-stem from Proto-Celtic *brusnos, genitive singular of *brusū (“belly, breast”).


nant

Middle Breton: nant

Breton: ant

Old Cornish: nans

Cornish: nans

Middle Welsh: nant

Welsh: nant

From Proto-Celtic *nantos, *nantus (“stream, valley”).


merx

Breton: merc'h

Cornish: myrgh

Welsh: merch


eskob

Middle Breton: eskop

Breton: eskob

Old Cornish: escop

Middle Cornish: epskop (relatinized)

Cornish: epskop

Old Welsh: escop

Middle Welsh: esgob

Welsh: esgob

Borrowed from Late Latin episcopus, with elision of -pi-. Whether this elision took place in Brythonic or British Latin is not immediately clear since the Romance reflexes of episcopus frequently display elision as well, however the independent borrowing from Latin to Old Irish epscop suggests that this was an internal Brythonic development.


klog

Cornish: klog

Welsh: clog


gwellt

Old Breton: guelt

Breton: gwelt, geot

Cornish: gwels

Middle Welsh: gwellt

Welsh: gwellt


hil

Breton: hil

Cornish: hil

Welsh: hil


garan

Breton: garan

Old Cornish: garan

→ Cornish: garan (semi-learned)

Middle Welsh: garan

Welsh: garan

From Proto-Celtic *garanos (“crane, heron”), from Proto-Indo-European *gerh₂- (“to cry hoarsely”).


lledr

Old Breton: ledr

Middle Breton: lezr

Breton: lêr

Cornish: ledher

Middle Welsh: lledyr

Welsh: lledr

From Proto-Celtic *letrom. Cognate with Middle Irish lethar.


kax

Middle Breton: cauch

Breton: kaoc'h

Cornish: kawgh

Welsh: cach

From Proto-Celtic *kakkā or a masculine *kakkos, itself from Proto-Indo-European *kakka-.


mollt

Middle Breton: mout, maout

Breton: maout

Cornish: mols

Middle Welsh: mollt

Welsh: mollt


forð

Breton: forzh (“lane, track”)

Old Cornish: ford

Middle Cornish: fordh

Cornish: fordh

Old Welsh: ford

Middle Welsh: ffordd

Welsh: ffordd

Borrowed from Old English ford. Doublet of *rrɨd and *porθ.


edn

Middle Breton: ezn

Breton: evn

Old Cornish: hethen

Middle Cornish: edhyn, ethen

Cornish: edhen

Middle Welsh: edyn

Welsh: edn


-jad

Old Breton: -iat

Old Cornish: -iat

Old Welsh: -iat

Middle Welsh: -iad

Welsh: -iad

From Proto-Celtic *-yatis, extended variant of Proto-Celtic *-atis. Cognate with Old Irish -(a)id.


paladr

Middle Welsh: pelydr

Welsh: paladr

From Proto-Celtic *kʷalatrom. Cognate with Old Irish celtair.


lliw

Old Breton: liu, liou

Middle Breton: liu

Breton: liv

Old Cornish: liu

Middle Cornish: lyw

Cornish: liw

Old Welsh: liu

Middle Welsh: lliw

Welsh: lliw

From Proto-Celtic *līwos, from Proto-Indo-European *slih₂-wó-s, from *(s)leh₃y- + *-wós.


mėgin

Middle Breton: meguin

Breton: megin, begin

Old Cornish: mygen

Cornish: mygenow, meginow pl

Middle Welsh: megin

Welsh: megin

Unknown; possibly related to Proto-Germanic *magô (“stomach”), Russian мошна (mošna, “pouch, purse”), perhaps from Proto-Indo-European *mak-.


neβ̃

Old Breton: nem

Middle Breton: neff

Breton: neñv

Old Cornish: nef

Cornish: nev

Old Welsh: nem

Middle Welsh: nef

Welsh: nef

From Proto-Celtic *nemos, from Proto-Indo-European *nébʰos.


tɨβ̃uɨl

Old Breton: temoel

Middle Breton: teffal

Breton: teñval

Old Cornish: tiwoulgou

Middle Cornish: teul, tevle

Cornish: tewl, tewal

Old Welsh: timuil

Welsh: tywyll

From earlier Proto-Brythonic *temēl(os), from Proto-Celtic *temeslos.


ėiriβ̃

Middle Welsh: eirif

From earlier Proto-Brythonic *aðrīm-, from Proto-Celtic *ad- + the masculine form of *rīmā (“number”).


llọβ̃

Old Breton: lom-

Old Cornish: lof

Cornish: leuv

desctree

Old Welsh: lau
Middle Welsh: llaw
Welsh: llaw


llọr

Old Breton: lor

Breton: leur

Old Cornish: lor

Cornish: leur

Old Welsh: laur

Middle Welsh: llawr, llaur

Welsh: llawr


llʉɣ

Old Breton: *lu (in toponyms)

Breton: lu

Old Cornish: luu

Cornish: lu

Middle Welsh: llu

Welsh: llu


llann

Middle Breton: lann

Cornish: lann

Old Welsh: lann

Middle Welsh: llann

Welsh: llan


puɨs

Breton: pouez

Middle Cornish: poys, pos, poos

Cornish: poos

Middle Welsh: pwys

Welsh: pwys

Borrowed from Vulgar Latin *pēsum, from Latin pēnsum. Parallel borrowing with Middle Irish pís (“name of a weight; pennyweight”).


broɣ

Old Breton: bro

Middle Breton: bro

Breton: bro

Cornish: bro

Middle Welsh: bro

Welsh: bro


marx

Old Breton: marh

Middle Breton: march

Breton: marc'h

Old Cornish: march

Middle Cornish: margh

Cornish: margh

Middle Welsh: march

Welsh: march


marxọg

Breton: marc'heg

Middle Cornish: marrek

Cornish: marghek

Middle Welsh: marchawc

Welsh: marchog

From Proto-Celtic *markākos. Equivalent to *marx (“horse”) + *-ọg.


aθreβ

Middle Welsh: athref

Welsh: athref


arɣant

Old Breton: argant

Middle Breton: archant

Breton: arc'hant

Cornish: arghans

Old Welsh: argant

Middle Welsh: ariant

Welsh: arian


bɨd

Old Breton: bit, bet

Breton: bed

Old Cornish: bit, bys

Cornish: bys, bes

Old Welsh: bid

Middle Welsh: byd

Welsh: byd


ebọl

Old Breton: ebol

Middle Breton: ebeul

Breton: ebeul

Old Cornish: ebol

Cornish: ebel

Middle Welsh: ebawl

Welsh: ebol

From Early Brythonic *epālos, from Proto-Celtic *ekʷālos.


prenn

Old Breton: pren

Middle Breton: prenn

Breton: prenn

Old Cornish: pren

Cornish: prenn

Middle Welsh: prenn

Welsh: pren

Cumbric: *prenn


tʉd

Middle Breton: tut

Breton: tud

Cornish: tus

Middle Welsh: tut

Welsh: tud

From Proto-Celtic *toutā, from Proto-Indo-European *tewtéh₂.


aberθ

Old Welsh: aperth

Middle Welsh: aberth

Welsh: aberth

From earlier Brittonic *abbertos, from Proto-Celtic *ad-bert-.


arθ

Old Breton: ard, arth

Breton: arzh

Cornish: arth

Middle Welsh: arth

Welsh: arth

Cumbric: *arth


nerθ

Old Breton: nerth

Middle Breton: nerz

Breton: nerzh

Middle Cornish: nerth

Cornish: nerth

Old Welsh: nerth

Middle Welsh: nerth

Welsh: nerth


perθ

Cornish: perth, Penberth (toponym)

Middle Welsh: perth

Welsh: perth

Pictish:

→ English: Perth (toponym)

From Proto-Celtic *kʷerxtā, from earlier assimilated *kʷerkʷ-t-, from Proto-Indo-European *pŕ̥kʷeh₂, *pérkus (“oak”) (compare Latin quercus, English fir).


rrɨd

Old Breton: rit

Breton: red (rare)

Old Cornish: rid

Middle Cornish: ryd

Cornish: rys

Old Welsh: rit

Middle Welsh: ryd, rid

Welsh: rhyd

From Proto-Celtic *ɸritus. Doublet of *forð and *porθ.


rrɨd

Old Breton:

Breton: red, rid

Old Cornish:

Middle Cornish:

Cornish: res

Old Welsh:

Middle Welsh: ret

Welsh: rhed

Inherited from Proto-Celtic *ritus. Cognate with Breton red, rid and Cornish res.


rriθ

Old Breton: arrith (in compound)

Middle Breton: rez

Breton: rezh

Middle Welsh: rith

Welsh: rhith


breɣ

Middle Cornish: bre

Cornish: bre

Middle Breton: bre

Breton: bre

Middle Welsh: bre

Welsh: bre

Middle Breton: Bre

Cornish: Brea, Bray

Old Welsh: Bregion pl


brɨd

Cornish: brys

Middle Welsh: bryd

Welsh: bryd


briθ

Old Breton: brith

desc

Middle Welsh: brythron (“magic wand”), lledfrith (“delusion, illusion”) (in compounds)

Welsh: lledrith


buɨd

Middle Breton: boet, bouet

Breton: boued

Old Cornish: buit

Cornish: boos, boys

Middle Welsh: bwyt

Welsh: bwyd


lleɣ

Old Breton: le

Breton: le

Cornish: le

Middle Welsh: lle

Welsh: lle


kömroɣ

Breton: keñvroad, keñvroiz (“compatriot”)

Cumbric: *Cumbri

→ Old English: Cumberland, Cumbraland, Cumerland

Middle English: Cumberlond, Cumberland, Cumbreland

English: Cumberland

Middle English: Cumbria

English: Cumbria

Middle Welsh: Kymry (“Wales”)

Welsh: Cymru (“Wales”), Cymro (“Welshman”)

→ Medieval Latin: Cambria

→ English: Cambria

From earlier Brythonic *kombrogis, equivalent to *köβ̃- + *broɣ (“he from an area”).


aradr

Middle Breton: arazr

Breton: arar

Old Cornish: aradar

Cornish: arader

Old Welsh: ara⟨ter⟩

Middle Welsh: aradr

Welsh: aradr

From Proto-Celtic *aratrom, from Proto-Indo-European *h₂érh₃trom.


gwur

Middle Breton: *gur

Breton: gour

Old Cornish: uir

Cornish: gour

Old Welsh: gur

Middle Welsh: gwr
Welsh: gŵr

From Proto-Celtic *wiros, from Proto-Indo-European *wiHrós.


brɨɣėntin

Old Breton: brientin, brientinion

Middle Cornish: brentyn, bryntyn

Middle Welsh: brenhin
Welsh: brenin

desctree

→ Old Irish: Brénainn
Irish: Bréanainn
→ Latin: Brendanus
Galician: Brandán
→ Irish: Breandán
→ English: Brendan

From Proto-Celtic *brigantīnos, probably meaning "high one," derivative of *brigantī (“high, exalted”).


prɨβ̃

Middle Breton: preff

Breton: preñv

Old Cornish: prif

Middle Cornish: pref

Cornish: pryv, prev

Old Welsh: prem

Middle Welsh: pryf

Welsh: pryf

From earlier *primis, from Proto-Celtic *kʷrimis, from Proto-Indo-European *kʷŕ̥mis.


prɨd

Middle Breton: pret

Breton: pred

Old Cornish: prit

Cornish: prys

Middle Welsh: pryd, pryt

Welsh: pryd

From Proto-Celtic *kʷritus, from pre-Celtic *kʷr̥tus, a tu-stem derived from Proto-Indo-European *kʷer- (“to make, cause”). Cognate with Old Irish cruth (“shape, form”).
GPC separates Welsh pryd in the "time, moment" and "face, appearance" senses, and expresses doubt at whether they are etymologically related.


prið

Old Breton: pri

Middle Breton: pri

Breton: pri

Cornish: pri

Middle Welsh: pridd

Welsh: pridd


gwɨnt

Middle Breton: guent

Breton: gwent

Old Cornish: guins

Cornish: gwyns

Middle Welsh: gwynt

Welsh: gwynt


gwɨð

Old Breton: guid

Middle Breton: guez

Breton: gwez

Cornish: gwydh

Old Welsh: guid

Middle Welsh: gwydd

Welsh: gwŷdd


arβ̃or

Middle Breton: armor, aruor

Middle Welsh: arfor

Welsh: arfor


glɨnn

Middle Breton: glenn

Breton: glen

Cornish: glynn, glydn

Middle Welsh: glynn

Welsh: glyn

From Proto-Celtic *glendos. Related to Proto-Germanic *klintaz.


llɨdaw

Old Breton: Letau

Breton: Ledav

→ French: Létavie

Cornish: Lesow

Old Welsh: Litau

Welsh: Llydaw

→ Old English: *Lidwīc

desc

Old English: Lidwīccas, Lidwīcingas (“Bretons”)

From Proto-Celtic *ɸlitawī, from Proto-Indo-European *pelh₂k- (“to spread out flat”) or more likely *pleth₂- (“flat”).


gwleð

Old Welsh: guled

Middle Welsh: gwledd

Welsh: gwledd


ėlβɨð

Old Welsh: elbid

Middle Welsh: eluit, eluyd

Welsh: elfydd


treβ

Old Breton: treff

Breton: trev

Middle Welsh: tref

Welsh: tref, tre

Cumbric: *trev


aβon

Middle Breton: auon

Breton: aven

Cornish: avon

Middle Welsh: afon

Welsh: afon

→ English: Avon

→ Scots: A'an

From pre-Proto-Brythonic *abonā, rebuilt ā-stem from Proto-Celtic *abonos, genitive singular of *abū (“river”).


aɨr

Old Breton: air

Old Cornish: hair

Old Welsh: hair

Middle Welsh: aer


gwogleð

Breton: gougleiz

Cornish: gogledh

Middle Welsh: gogled

Welsh: gogledd

From Proto-Celtic *uɸokliyom, cognate with Old Irish fochlae. By surface analysis, *gwo- + *kleð.


brɨɣėnt

Old Breton: Brient (personal name)

→ Middle Irish: Brían

desctree

Irish: Brian
English: Brian, Bryan, Bryon
→ Cebuano: Brian
→ Danish: Brian
→ Faroese: Brian
→ French: Brian

Old Welsh: bryeint

Middle Welsh: breeint

Welsh: braint


nɨθ

Middle Breton: nez

Breton: neizh, nezh

Old Cornish: neid

Middle Cornish: nyth

Cornish: neyth

Middle Welsh: nyth

Welsh: nyth

From Proto-Celtic *nizdos, from Proto-Indo-European *nisdós.


noɨθ

Old Breton: noit

Middle Breton: noaz

Breton: noazh

Cornish: noth

Middle Welsh: noeth

Welsh: noeth


gėr

Middle Breton: guer

Breton: ger

Cornish: ger

Middle Welsh: geir

Welsh: gair

From Proto-Celtic *garyos, related to *garyeti (“to call, cry”).


rriɣėn

Breton: rouanez?

Cornish: ruvanes?

Middle Welsh: riein (“maiden”)

Welsh: rhiain


hɨnt

Old Breton: hint

Middle Breton: hent

Breton: hent

Middle Cornish: hyns

Cornish: hyns, (RLC) hens

Middle Welsh: hint, hynt

Welsh: hynt


gwėɣin

Middle Breton: gouhin

Breton: gouin

→? French: gouine

Old Cornish: guein

Middle Cornish: goyn, gon

Cornish: goen

Middle Welsh: gwein

Welsh: gwain

Borrowed from Vulgar Latin văgīna, from Latin vāgīna (“sheath, scabbard”) with pretonic shortening of ā. Parallel borrowing with Old Irish faigen (“sheath, scabbard”).


dremm

Middle Breton: drem

Breton: dremm

Middle Welsh: trem, drem (irregular initial t-)

From Proto-Celtic *drixsmā, from pre-Celtic *dr̥ḱ(s)meh₂.


kėnėw

Old Breton: ceneuan, compare Rikeneu (PN)

Middle Breton: kenou

Breton: kenow

Middle Welsh: ceneu

Welsh: cenau, cenaw

From earlier *kanawī, from Proto-Celtic *kanawū.


karr

Old Breton: carr

Middle Breton: carr

Breton: karr

Cornish: karr

Middle Welsh: carr

Welsh: car


kareð

Middle Breton: carez

Cornish: cara

Old Welsh: cared

Middle Welsh: cared, karet

Welsh: caredd


koɨd

Middle Breton: coat

Breton: koad

Old Cornish: cuit

Middle Cornish: coys

Cornish: koos

Old Welsh: coit

Middle Welsh: coet

Welsh: coed

Cumbric: cɛ̄d

From Proto-Celtic *kaitos, from Proto-Indo-European *kayt-, *ḱayt- (“forest, wasteland, pasture”). Cognate with Proto-Germanic *haiþī (“heath, wasteland”), as well as perhaps Latin bū-cētum (“pastureland”, literally “cow-pasture”), Albanian kath (“type of wheat”), kashtë (“straw”).


kėljọg

Old Breton: kelihuc

Middle Breton: kilhog, kilheg

Breton: kilhog

Old Cornish: chelioc

Middle Cornish: celioc, kullyek, colyek

Cornish: kulyek

Middle Welsh: keilyawc

Welsh: ceiliog, ceilog


kantl

Middle Breton: quentel

Breton: kentel

Middle Welsh: kathyl, kathl

Welsh: cathl


dadl

Old Breton: dadl

Breton: dael

Middle Welsh: dadl

Welsh: dadl


duɨw

Old Breton: *doi (in compound)

Middle Breton: doe

Breton: doue

Old Cornish: duy

Middle Cornish: dew, deu

Cornish: duw

Old Welsh: duiu

Middle Welsh: duw

Welsh: duw


gwlan

Middle Breton: glan, gloan

Breton: gloan

Old Cornish: gluan

Middle Cornish: glan, glawn

Cornish: gwlan

Old Welsh: gulan

Middle Welsh: gwlan

Welsh: gwlân

From Proto-Celtic *wlanā, from Proto-Indo-European *h₂wĺ̥h₁neh₂.


ammaɨθ

Old Breton: ambaith

Cornish: ammeth

Middle Welsh: amaeth

Welsh: amaeth


taradr

Middle Breton: tarazr, talazr

Breton: tarar

Cornish: tardar

Old Welsh: tarater

Welsh: taradr

From Proto-Celtic *taratrom, from pre-Celtic *terh₁tro-. Cognate with Ancient Greek τέρετρον (téretron, “borer”), Latin terebra (“borer”).


anw

Old Breton: anu

Middle Breton: hanu, anff

Breton: anv

Cornish: hanow

Old Welsh: anu
Middle Welsh: enw
Welsh: enw


garr

Middle Breton: garr

Breton: gar

Middle Cornish: gar

Cornish: garr

Middle Welsh: garr

Welsh: gar


kedor

Middle Breton: quaezour

Cornish: kedhor

Old Welsh: caitoir

Middle Welsh: cedor

Welsh: cedor


ɨβ

Welsh: yf


nėθ

Old Breton: nith

Middle Breton: nyz

Breton: nizh

Old Cornish: noit

Cornish: nith

Old Welsh:

Middle Welsh: nith

Welsh: nith


toɨs

Middle Breton: toas

Breton: toas, toaz

Cornish: toos

Middle Welsh: toes

Welsh: toes


bɨw

Welsh: byw

From Proto-Celtic *biwos, from Proto-Indo-European *gʷih₃wós.


krʉn

Breton: kroc'hen

Old Welsh: groen

Welsh: croen

From Proto-Celtic *krok(ke)no- (“skin”), probably loaned from a non-Indo-European substrate language. However, compare Proto-Germanic *hrugjaz (“ridge, back, spine”) and German Krug.


llėβėrjad

Old Breton: torleberieti

Old Cornish: gouleueriat, guirleueriat


möxjad

Middle Welsh: meichiad

Old Breton: Uinmochiat

From *mox + *-jad, from Proto-Celtic *mokk(w)yatis. Cognate with Old Irish muccaid.


kɵ̇nniβ̃jad

Middle Welsh: cynifiad

From *kɵ̇nniβ̃ + *-jad, from Proto-Celtic *konsnīm(w)yatis. Cognate with Old Irish cosnamaid.


bʉgöl

Middle Breton: buguel, bugel

Breton: bugel

Cornish: bugel

Middle Welsh: bugeil

Welsh: bugail


bulx

Old Welsh: bulch

Welsh: fwlch


gwɨwer

Breton: gwiñver

Cornish: gwiwer

Welsh: gwiwer


tɨɣ

Old Breton: tig

Breton: ti

Old Cornish: ti

Cornish: chi, chy

Middle Welsh: ty

Welsh: tŷ

From Proto-Celtic *tegos, from Proto-Indo-European *(s)teg- (“cover”).


gaβl

Old Breton: gabl

Breton: gaol

Cornish: gowl

Middle Welsh: gafl

Welsh: gafl

⇒ Welsh: Yr Eifl (from the dual form *h(ɨ/e)nn ɣėβl < *sindī gablī < *sindai gablai)


brox

Middle Breton: broc'h

Breton: broc'h

Old Cornish: broch

Cornish: brogh

Middle Welsh: broch

Welsh: broch


karw

Middle Breton: caro, qaro

Breton: karv

Old Cornish: karow

Cornish: karow

Old Welsh: caru

Middle Welsh: carw

Welsh: carw


gworuɨð

Middle Welsh: gorwyð

Welsh: gorwydd


gaβr

Old Breton: gabr

Breton: gaor, gavr

Old Cornish: gauar

Cornish: gaver

Middle Welsh: gauar

Welsh: gafr


jọw

Middle Breton: yeu, ieo

Breton: yev

Cornish: yew

Old Welsh: iou

Welsh: iau

From Proto-Celtic *yugom, from Proto-Indo-European *yugóm.


aβal

Old Breton: abal

Middle Breton: aval

Breton: aval

Cornish: aval

Middle Welsh: aual

Welsh: afal


klʉst

Middle Welsh: clust

Welsh: clust

From Proto-Celtic *kloustā, from Proto-Indo-European *ḱlow-steh₂, from *ḱlew- (“to hear”).


llowern

Old Breton: louuern

Middle Breton: louarn

Breton: louarn (“fox”), lowern, luhern

Old Cornish: louuern (“vulpes”)

Cornish: lowarn (“fox”)

Old Welsh: louern

Middle Welsh: llewyrn (“foxes”)

Welsh: llwyrn (“will o' the wisp”)


lloɨr

Old Breton: loir, loer

Breton: loar, loer

Old Cornish: luir

Middle Cornish: lor

Cornish: loor

Old Welsh: loyr

Welsh: lloer

Uncertain; possibly from Proto-Celtic *(s)lairā, from Proto-Indo-European *(s)leh₃y- (“plum-coloured, blueish”), whence Latin lūridus (“bruise-colored, pale yellow”),. Alternatively from Proto-Celtic *lugrā from Proto-Indo-European *lewk- (“bright; to shine”), or perhaps from Proto-Indo-European *lewg- (“to bend, twist”).


jaɣ

Cornish: yey

Welsh: iâ

From Proto-Celtic *yegis, from Proto-Indo-European *h₁yeg-.


grọn

Breton: greun

Cornish: greun

Welsh: grawn


grọw

Middle Breton: grouanenn

Breton: groa, gro, grouan

→ English: growan

Old Cornish: grou

Cornish: grow

Welsh: gro


guɨstl

Old Breton: guistl

Middle Breton: goestl

Breton: gouestl

Old Cornish: guistel

Cornish: gostel

Middle Welsh: gwystyl, gwystl

Welsh: gwystl

From Proto-Celtic *geistlos, from Proto-Indo-European *gʰeydʰ- (“desire, wait for”).


klọw

Old Breton: clou

Middle Breton: clou

Breton: klao, klow

Middle Welsh: clo

Welsh: clo


muɨn

Middle Breton: *men

⇒ Breton: mengleuz (“quarry”)

Cornish: moon (“mineral”)

Middle Welsh: mwyn

Welsh: mwyn


haβ̃

Old Breton: ham

Middle Breton: haff

Breton: hañv

Old Cornish: haf

Cornish: hav

Old Welsh: ham

Middle Welsh: haf

Welsh: haf


froɨn

Old Breton: fron

Middle Breton: froan, fron

Breton: froen (“nostril”)

Middle Welsh: ffroen

Welsh: ffroen


llug

Old Breton: loc

Middle Welsh: llyg

Welsh: llyg (“shrew”)


kaθ

Breton: kazh, kaz

Cornish: kath, cath

Welsh: cath

From Proto-Celtic *kattā, of non-Indo-European origin and traditionally thought to be from an Afroasiatic language, such as Nubian *kadīs (“cat”). Because of clear parallels in Latin cattus and Proto-Germanic *kattuz, the language family that the word first entered is unclear.


glọw

Breton: glaou

Cornish: glow

Welsh: glo

From Proto-Celtic *glāwos, from Proto-Indo-European *ǵʰel-. See also Proto-Germanic *glōaną (“to glow”).


klọr

Breton: kleur

Old Welsh: claur

Welsh: clawr

From Proto-Celtic *klāros, likely cognate with Ancient Greek κλῆρος (klêros), from Proto-Indo-European *kleh₂- (“to lay out”), from *kelh₂- (“to hit, cut down”).


barð

Middle Breton: barz

Breton: barzh

Old Cornish: barth

Cornish: bardh

Middle Welsh: bardd

Welsh: bardd


gwrʉg

Cornish: grug

Middle Breton: groegan

Middle Welsh: gerug, gwrug

Welsh: grug


llex

Breton: lec'h

Cornish: legh

Middle Welsh: llech

Welsh: llech


molọd

Middle Welsh: molaut

Welsh: molawd

From Proto-Celtic *molātus, verbal noun to the above verb.


düβrgi

Breton: dourgi

Old Cornish: doferghi

Cornish: dowrgi

Welsh: dyfrgi, dwrgi

From Proto-Celtic *dubrokū. Equivalent to *duβr (“water”) + *ki (“dog”).


kreθ

Middle Welsh: kreth

Welsh: creth


rriβ̃

Cornish: riv

Welsh: rhif


ɨnɨs

Old Breton: inis

Middle Breton: enes

Breton: enez

Cornish: enys

Old Welsh: inis

Middle Welsh: ynys

Welsh: ynys


Brɨθon

Breton: brezhon, Brezhon

Middle Cornish: Brethon

Cornish: Brython

Middle Welsh: Brython

Welsh: Brython

→ English: Brython

⇒ English: Brythonic

From earlier *Britton-, borrowed from the Vulgar Latin Brittōn-, oblique stem of Latin Brittō. Doublet of *Prɨdėn (“Britain”).

Briton, speaker of a British Celtic language


rreiθ

Middle Breton: rez, reiz

Cornish: ryth

Middle Welsh: reyth

Welsh: rhaith

From Proto-Celtic *rextus. Compare Old Irish recht and Modern Irish reacht.


llað

Middle Welsh: lladd

Welsh: lladd

From Proto-Celtic *sladyā, derived from *sladyeti.


daβ̃ad

Breton: dañvad

Cornish: davas

Welsh: dafad


rrod

Breton: rod

Cornish: ros

Welsh: rhod


gweβl

Cornish: gwevel

Middle Breton: guefl

Welsh: gwefl


puɨll

Breton: poell

Cornish: poll

Welsh: pwyll


gwɨbod

Old Breton: gudbut

Middle Breton: gouzuout

Breton: gouzout

Old Cornish: godbod

Middle Cornish: godhvos

Cornish: godhvos/goffos

Middle Welsh: gwybot

Welsh: gwybod

From the compound of *gwɨd- + *bod (“to be”), earlier *wibbutā < *widbutā, from Proto-Celtic *wid-, *windeti (“to know, to see”) + *butā, ultimately from Proto-Indo-European *weyd- (“to see, to know”) + *bʰuH- (“to be, become”).


rrix

Middle Welsh: ri

Welsh: rhi

Old Breton: ri


drüw

Old Cornish: druw

Middle Welsh: dryw

Welsh: dryw

→ Old English: drȳ (see there for further descendants)

From Proto-Celtic *druwits. By itself, Celtic *druwits should have given *druw, as final i-affection did not affect u. In the original oblique stem *druwid-, however, internal i-affection occurred, which did affect u. The oblique stem was generalised to the nominative singular before the loss of final syllables. Compare also *süw.


parθ

Old Breton: parth

Middle Breton: parz

Breton: parzh

Middle Cornish: parth

Cornish: parth

Middle Welsh: parth

Welsh: parth

Borrowed from Latin pars (“part, portion”). Parallel borrowing with Middle Irish pairt (“part”), pars (“communion wafer”).


gwrėg

Middle Breton: gruec

Breton: gwreg

Old Cornish: greg, grueg

Middle Cornish: gurek

Cornish: gwreg

Middle Welsh: gureic, gwreic

Welsh: gwraig

From Proto-Celtic *wrakī or Proto-Celtic *gʷrakī. In the former case related to Old Irish frac (“woman”), and in the latter case perhaps related to Middle Irish *grúac (“hair”). For similar sense development, see Scottish Gaelic gruagach (“maiden, woman”), which evolved from gruag, as unmarried women did not cover their hair.


aβaln

Breton: avalenn

Cornish: avalen

Welsh: afallen


ɨmperọdr

Middle Breton: impalaezr

Breton: impalaer

Old Welsh: ymerawdyr

Middle Welsh: ymherodr

Welsh: ymherodr

Borrowed from Latin imperātor, ultimately from Proto-Indo-European *per- (“to go forth, traverse”), whence related Proto-Brythonic *rrɨd (“ford”). Parallel borrowing with Cornish emperour (“emperor”) (via French), Old Irish impere, impire (“emperor”).


talx

Old Cornish: talch (“bran”)

desc

Welsh: talch (“hulled grain, oatmeal; fragments”)

From Proto-Celtic *talskos, from earlier *talkskos, from Proto-Indo-European *tl̥k-s-ḱos, from *telk- (“to thrust, strike”). Cognate with Proto-Slavic *telťi (“to pound”), Lithuanian ti̇̀lkti (“to be tame”).


gwɨr

Cornish: gwer

Welsh: gwŷr


ėmmėɨθ

Welsh: emeith


ėnwėn

Cornish: henwyn


ėrėdr

Breton: erer

Welsh: erydr


bėrð

Cornish: berdh

Welsh: beirdd


brėn

Middle Breton: briny

Breton: brini

Middle Cornish: bryny

Cornish: brini, briny

Old Welsh: brein

Middle Welsh: brein

Welsh: brain


dėβ̃ėd

Breton: deñved

Cornish: deves

Welsh: defaid


gwėlėdr

Welsh: gwelydr


gwrageð

Breton: gwagez

Cornish: gwragedh

Welsh: gwragedd


hɨntow

Breton: hentoù

Cornish: henjow


kėrr

Welsh: ceir


kanawon

qual

Welsh: cenawon (first-syllable vowel modified by analogy)


marxọgjon

Breton: marc'héien

Cornish: marghogyon

Welsh: marchogion


parθow

Cornish: parthow

Welsh: parthau


rriɣaneð

Welsh: rhianedd


tėrėdr

Breton: terer

Cornish: terder

Welsh: terydr


tėd

Welsh: taid


ėrθ

Welsh: eirth


bɨdow

Breton: bedoù

Cornish: bysow, besow


duβr

Middle Breton: dour

Breton: dour

Cornish: dowr

desctree

Middle Welsh: dwfyr, dwfuyr, dwr, dwuyr, dwvyr, dyfwr
Welsh: dwfr, dŵr

From Proto-Celtic *dubros, from Proto-Indo-European *dʰubʰrós.


ɨdn

Cornish: ydhyn


genow

Breton: genoù

Cornish: genyow, ganow

Welsh: genau


blọd

Breton: bleud

Cornish: bleus

Welsh: blawd

From Proto-Celtic *mlātos, from Proto-Indo-European *melh₂-.


blọd

Old Breton: bloduu

Middle Breton: bleuzff

Breton: bleuñv

Old Cornish: blodon

Cornish: bleujen

Middle Welsh: blawt

Welsh: blodyn

From Proto-Celtic *blātus, from Proto-Indo-European *bʰleh₃-.


gwliθ

Middle Breton: gluiz

Breton: glizh

Cornish: gluth

Middle Welsh: gwlith

Welsh: gwlith

From Proto-Celtic *wlixtVs, from Proto-Indo-European *wlikʷ-tV́-s, from *wleykʷ- (“moist; to wet”).


gwɨs

Welsh: gwŷs

From Proto-Celtic *wissus, from Proto-Indo-European *wéydtus.


llugod

Middle Breton: logod, logot

Breton: logod

Old Cornish: *logot (from the attested singulative logoden)

Middle Cornish: logos

Cornish: logos

Middle Welsh: llygod

Welsh: llygod

From Proto-Celtic *lukotes, plural of *lukūts. Equivalent to *llug + *-od.


gweðw

Old Cornish: guedeu

Cornish: gwedhow

Middle Welsh: gweðw, gwyðw

Welsh: gweddw

From Proto-Celtic *widwā, from Proto-Indo-European *h₁widʰéwh₂.


frud

Old Breton: frut

Breton: froud

Old Cornish: frot

Cornish: fros

Middle Welsh: ffrwt

Welsh: ffrwd


skọd

Breton: skeud

Old Cornish: scod

Cornish: skeus

Middle Welsh: ysgawt

Welsh: ysgod


krow

Middle Cornish: crow

Cornish: krow

Middle Welsh: creu

Welsh: crau

From Proto-Celtic *krūs, from Proto-Indo-European *kréwh₂s.


meβl

⇒ Old Breton: meplaom

Cornish: mewl

Middle Welsh: meuyl

Welsh: mefl


blėð

Old Breton: bleid

Middle Breton: bleiz

Breton: bleiz

Old Cornish: bleit

Cornish: bleydh

Middle Welsh: bleidd

Welsh: blaidd


gwollt

Old Breton: guolt

Old Cornish: gols

Cornish: gols

Welsh: gwallt


rrɨx

Old Breton: rec

Middle Breton: rec

Breton: re

Middle Welsh: rych, rhych

Welsh: rhych


rros

Middle Breton: ros

Cornish: ros

Middle Welsh: ros

Welsh: rhos

Cumbric: *ros


maɣɨn

Cornish: men

Old Breton: main

Middle Breton: men

Breton: maen (see there for further descendants)

Old Welsh:

Middle Welsh: maen

Welsh: maen


bedu

Middle Breton: bezu

Cornish: besow

Middle Welsh: bedwen sg

Welsh: bedw


jeiθ

Breton: yezh

Cornish: yeth

Middle Welsh: ieith

Welsh: iaith

From Proto-Celtic *yextis, from Proto-Indo-European *yek-.


hwoɨr

Old Breton: guoer

Middle Breton: hoer

Breton: c'hoar

Old Cornish: huir

Cornish: hwor

Middle Welsh: chwaer

Welsh: chwaer


bọreɣ

Middle Breton: beure

Breton: beure

Middle Welsh: bore

Welsh: bore

→ Cornish: bore


towɨssọg

Old Breton: toguisoc

Breton: tevezeg

Middle Welsh: tywyssawc (“prince”)

Welsh: tywysog

From Proto-Celtic *towissākos. Equivalent to *togwɨs (“leadership”) + *-ọg.


aml

Middle Welsh: amyl


dọn

Welsh: dawn

From Proto-Celtic *dānus. Cognate with Old Irish dán.


bolɣ

Middle Breton: bolc'h

Breton: bolc'h

Cornish: bolgh

Middle Welsh: boly, boliau, byly

Welsh: bol, bola


gwɨmon

Old Breton: goumon

Middle Breton: gwemon

→ Middle French: goumon

French: goémon

Cornish: gommon, gobmon

Welsh: gwymon


oged

Middle Breton: oguet

Breton: oged

Old Cornish: ocet

Cornish: oges

Middle Welsh: ocet

Welsh: oged


köll

Breton: kell

Cornish: kell

Middle Welsh: keill

Welsh: caill

From Vulgar Latin *cōlea n pl (“testicle”).


hʉn

Middle Breton: hun

Old Cornish: hun

Middle Cornish: hun

Middle Welsh: hun

Welsh: hun


oɨs

Old Cornish: huis

Cornish: oos

Old Welsh: ois

Welsh: oes


oɨd

Old Breton: oit

Middle Breton: oet

Breton: oad

Cornish: ooj

Old Welsh: oit

Middle Welsh: oet

Welsh: oed


ėgin

Breton: egin

Middle Welsh: egin

Welsh: egin


gwuɨlann

Old Breton: guilannou (plural)

Middle Breton: goelann

Breton: gouelan

→ Middle French: gaellans, goilant

French: goéland

Old Cornish: guilan

→ Cornish: golan (semi-learned)

Middle Welsh: gwylan

Welsh: gwylan

→ Middle English: gulle

English: gull

⇒ English: seagull

From Proto-Celtic *weilannā, a variant of *wailannā.


hwegr

Old Cornish: hweger

Cornish: hweger

Welsh: chwegr

From Proto-Celtic *swekrū, from Proto-Indo-European *sweḱrúh₂. Cognate with Latin socrus.


jʉð

Middle Welsh: ut, ud, udd

Welsh: udd

From Proto-Celtic *youdos, from Proto-Indo-European *Hyewdʰ-, an extension of *h₂yew- (“justice, law”).


maɣl

Middle Welsh: mael

From Proto-Celtic *maglos (“noble, chief”).


jorx

Old Breton: iorch

Middle Breton: yourch

Breton: yourc'h

Old Cornish: yorch

Cornish: yorgh

Middle Welsh: iwrch


hiraɨθ

Breton: hiraezh

Cornish: hireth

Welsh: hiraeth

From Proto-Celtic *sīraxto-. Cognate with Gaulish siraxta (“longing”) and Old Irish sírecht.

nostalgia, longing, yearning, homesickness


kaɨr

Old Breton: caer, Car- (in toponyms)

Middle Breton: kaer (“town, city”)

Breton: kêr

Middle Cornish: caer

Cornish: ker

Old Welsh: cair

Middle Welsh: caer

Welsh: caer

Cumbric: cayr

* GPC and Matasović derive this from Proto-Celtic *kagros (“fort”), being a structure which encloses or 'takes' an amount of land, from the Proto-Indo-European root *kagʰ- (“take, seize”). The term *kaɨ (“enclosure”) with related meaning is derived from the same root.
* Holmer and Schrijver instead connect this with Old Irish cathair, reconstructing a common Celtic *kastrixs. Holmer further elaborates that the common Celtic word is borrowed from Latin castrum (“fort”).


kaɨ

Old Breton: cai

Middle Breton: quae

Breton: kae

Cornish: ke

Middle Welsh: kay, kae

Welsh: cae

From Proto-Celtic *kagyom (“pen, enclosure”), from Proto-Indo-European *kagʰyóm. Cognate with Gaulish *kagyom and Old Irish caí.


kluɨd

Middle Breton: klouet

Old Cornish: cluit

Middle Welsh: clwyt

Welsh: clwyd


dɨð

Breton: deiz

Cornish: dydh

Old Welsh: did
Middle Welsh: dyð
Welsh: dydd

From Proto-Celtic *dyīus (“day”), from Proto-Indo-European *dyḗws (“sky, heaven”).


hwuɨs

Middle Breton: hues

Breton: c’houez

Cornish: hwys

Middle Welsh: chuis

Welsh: chwys


toɣ

Middle Breton: toenn

Breton: to

Old Cornish: to

Welsh: to

From Proto-Celtic *togos, from Proto-Indo-European *(s)teg-. Cognate with Old Irish tugae.


gwuɨð

Old Breton: gued

Middle Breton: goez

Breton: gouez

Middle Welsh: gwydd

Welsh: gŵydd

appearance, presence, face, sight, image


nọβ̃

Middle Breton: neuff

Breton: neuñv

Middle Welsh: nawf

Welsh: nawf

From Proto-Celtic *snāmos. Cognate with Middle Irish snám.


llaθ

Old Breton: lath

Breton: lazh

Cornish: lath

Welsh: llath

From Proto-Celtic *slattā. Cognate with Old Irish slat.

rod, staff, stick, spear, beam, rafter, pole


lluɨɣ

Old Breton: loi

Middle Breton: loa

Breton: loa

Old Cornish: loe

Cornish: lo

Middle Welsh: llwy

Welsh: llwy

From Proto-Celtic *leigā. Cognate with Old Irish líag.


ehọg

Middle Breton: eheuc

Breton: eog

Old Cornish: ehoc

Middle Cornish: ehuac

Cornish: eghek

Middle Welsh: ehawc

Welsh: eog

From Proto-Celtic *esākos, an irregular variation of *esoxs.


llowadr

Old Breton:

Middle Breton: lovazr

Breton: laouer

From Proto-Celtic *lowatrom. Cognate with Old Irish lóathar.


kilɨð

Middle Welsh: cilit, kilid

Welsh: cilydd

Old Breton: kiled

Breton: kile

Cornish: kila

From Proto-Celtic *keiliyos. Cognate with Old Irish céile.


peθ

Middle Breton: pez

Breton: pezh

Cornish: peth, pyth

Old Welsh: ped

Middle Welsh: peth

Welsh: peth

Pictish:

→ Scottish Gaelic: pett

→ English: peat

From Proto-Celtic *kʷezdis, of uncertain derivation. Cognate with Old Irish cuit and Gaulish *pettiā.


gwoɨθl

Middle Welsh: gwaethl

Welsh: gwaethl

From Proto-Celtic *woxtlom, from Proto-Indo-European *wekʷ- (“to speak, sound out”). Cognate with Old Irish focul.


staɨn

Breton: staen

Cornish: sten

Welsh: ystaen


lled

desc

Middle Breton: let, led (“large”), led (“greatness”)

Breton: led

Cornish: les

Middle Welsh: lled (“breadth, width, half”)

Welsh: lled

From Proto-Celtic *ɸletos. Cognate with Old Irish leth (“side”).


haβ̃areg

Middle Breton: havrek

Breton: havreg

Old Cornish: *havrek, Karrauerok

Cornish: Averack, Haverack, Caraverick

From *haβ̃ar + *-eg, from Proto-Celtic *samaros.


haβ̃ar

Cornish: havar

Welsh: hafar


eneb

Old Breton: enep

Middle Breton: enep

Breton: eneb, enep

Old Cornish: eneb

Cornish: enep

Old Welsh: enep

Welsh: wyneb, gwyneb


mönɨð

Old Breton: monid

Breton: menez

Old Cornish: menit

Cornish: menydh

Middle Welsh: mynyð

Welsh: mynydd

→ Middle Irish: moned, monad (found only in Scottish toponyms)

Scottish Gaelic: monadh


gwennọl

Old Breton: guennol

Middle Breton: guennel

Breton: gwennel

Old Cornish: guennol

Cornish: gwennel

Middle Welsh: gwennawl

Welsh: gwennol

From Proto-Celtic *wesnālā. Cognate with Old Irish fannall.


adėn

Welsh: adain

From Proto-Celtic *ɸatanī. Cognate with Old Irish ette.


meið

Old Breton: meid

Cornish: meith

Welsh: maidd

From Proto-Celtic *mezgos. Cognate with Middle Irish medc.


kruɨdr

Old Breton: croitir

Middle Breton: croezr

Old Cornish: croider

Old Welsh: cruitr

Welsh: crwydr

From Proto-Celtic *kreitros, from Proto-Indo-European *krey- (“to sift”). Cognate with Old Irish *críathar.


kuβ̃ruɨɣ

Old Breton: comreg

Breton: kevre

Cornish: kevren

Middle Welsh: kyfreieu

Welsh: cyfrwy

From Proto-Celtic *komreigom. Cognate with Old Irish cuimrech.


körxɨð

Old Breton: corcid

Middle Breton: quercheiz

Breton: kerc’heiz

Old Cornish: cherhit

Middle Cornish: kerghyth, keryth

Cornish: kerghydh

q

Middle Welsh: crychydd, crechydd (with metathesis, perhaps influenced by crehyr (whence Welsh crëyr))

Welsh: crychydd, crechydd

From an underlying Proto-Celtic *korkiyos, perhaps onomatopoeic in origin. Frequently compared with Old Irish corr (“heron”) (< *korxsV?), but Schrijver reasons that this cannot produce the Brythonic form and argues that this may be a descriptive name arising within Goidelic.


korug

Welsh: corwg

From Proto-Celtic *korukos, probably from Proto-Indo-European *(s)koro- (“leather”). Cognate with Middle Irish curach.


koɨs

Middle Welsh: coes

Welsh: coes

From Proto-Celtic *koxsā. Cognate with Old Irish cos.
Alternatively, could be considered a loanword from Latin coxa, but the semantics make an inheritance from Proto-Celtic more likely.


moruɨn

Cornish: moren

Welsh: morwyn

From Proto-Celtic *morēnā. Related to *merx (“daughter”).


mọdreb

Old Cornish: modereb

Cornish: modrep

Old Breton: motrep

Middle Breton: mozreb

Breton: moereb

Old Welsh: modreped (plural)

Middle Welsh: modryb

Welsh: modryb

From Proto-Celtic *mātrikʷā, from *mātīr (“mother”), from Proto-Indo-European *méh₂tēr.


hwuɨð

desc

Breton: c'hwez (“air used to inflate something, swelling, vanity”)

⇒ Breton: c'hwezañ

Middle Welsh: chwyd

Welsh: chwydd

From Proto-Celtic *sweidus. Cognate with Classical Gaelic siat, siad.


kalwon

Middle Breton: calon

Breton: kalon

Cornish: kolon

Middle Welsh: callon

Welsh: calon

From Proto-Celtic *kalwond-; compare Middle Welsh colweð (“breast, heart”) and possibly coluð (“instestines”) from the same root.


diweð

Breton: diwezh

Cornish: diwedh

Old Welsh: diued

Middle Welsh: diued

Welsh: diwedd

From Proto-Celtic *dīwedom; from *dī- (“from, away”) (See Proto-Indo-European *de) + *wedo- (“to lead”) (See *wedʰ-). Cognate with Old Irish díad.


ėrɣ

Middle Breton: erch

Breton: erc'h

Old Cornish: irch

Cornish: ergh

Middle Welsh: eiry

Welsh: eira, eiry

Uncertain; perhaps from Proto-Celtic *argyos (“white”), from Proto-Indo-European *h₂r̥ǵ-yó-s, from *h₂erǵ- (“white”) + *-yós, possible cognate with Gaulish *argyos (whence Latin personal name Argiotalus). Alternatively from Proto-Celtic *ɸargyos, *ɸargos (“sprinkling, spatter”) from Proto-Indo-European *spérg-o-s, from *sperg- (“to strew”) + *-os, cognate with Old Irish arg (“drop”), Latin spargō (“to scatter, shower”).


knud

Middle Breton: cnot

Welsh: cnwd

From Proto-Celtic *knutos. Cognate with Old Irish cnúas.


kʉl

Old Cornish: cul

Cornish: kul

Welsh: cul

From Proto-Celtic *koilos (“thin”), from Proto-Indo-European *koyHlo- (Latvian kails (“bare, naked”)). Cognate with Old Irish cáel.


bröɣɨr

Middle Welsh: breyr, brehyr

Welsh: brëyr

From Proto-Celtic *mrogirīxs, a compound of *mrogis (“country, region”) and *rīxs (“king”).


lluβoɣorθ

Middle Breton: luorz

Breton: liorzh

Old Cornish: luworch (misspelling of luworth)

Middle Cornish: lowarth

Old Welsh: luird (plural)

Middle Welsh: luarth

Welsh: lluarth

From Proto-Celtic *lubogortos, corresponding to *lloβ + *gorθ.


llüw

⇒ Breton: levier m (“pilot”)

Old Cornish: leu

Cornish: lew (“rudder”)

Old Welsh: liu

Middle Welsh: llyw m (“rudder, tail, leader, pilot”)

Welsh: llyw

From Proto-Celtic *ɸlowī. Cognate with Old Irish luí.


tuβ̃

Old Breton: tum

Breton: teñv

Welsh: twf


treβn

Welsh: trefn


argoɨd

Breton: argoad

Welsh: argoed


llėðjad

Welsh: lleiddiad


exoβneð

Welsh: ehofnedd


klėβ̃ɨd

Breton: kleñved

Old Cornish: clevet

Middle Cornish: cleves

Welsh: clefyd

From Proto-Celtic *klamitos, from the adjective *klamos (“ill”).


gwöniθ

Middle Breton: guiniz

Breton: gwinizh

Cornish: gwaneth

Middle Welsh: gwenith

Welsh: gwenith

From *gwo- (“under”) + *niθ (“winnowed; wheat”). Cognate with Old Irish cruithnecht (“wheat”).


kuβ̃oɨθ

Old Cornish: chefuid

Old Welsh: comoid

Middle Welsh: kyuoeth

Welsh: cyfoeth, cywoeth, cywaeth

From Proto-Celtic *komonxtom. Cognate with Old Irish cumachtae.


aɨron

Middle Welsh: aeron

Welsh: aeron

From Proto-Celtic *agronā, from a derivative of Proto-Indo-European *h₂ógr̥ (“berry”). Doublet of *eɨrin (“sloe”).


skuɨd

Breton: skoed

Cornish: skoes

Welsh: ysgwyd

From Proto-Celtic *skeitos. Cognate with Old Irish scíath.


knux

Old Breton: cnoch

Middle Breton: knech

Breton: krec'h

Welsh: cnwch

From Proto-Celtic *knukkos. Cognate with Old Irish cnocc.


kolɨn

Old Breton: colaenn

Middle Breton: quelenn

Breton: kelenn

Cornish: kelyn

Welsh: celyn

From Proto-Celtic *kolinnos. Cognate with Old Irish cuilenn.


gwölɨɣ

Breton: gwele

Cornish: gweli

Welsh: gwely

From Proto-Celtic *uɸo-legyom, from Proto-Indo-European *upo + *legʰ- (“to lie (down)”).


llugad

Old Breton: lagat

Middle Breton: lagat

Breton: lagad

Old Cornish: lagat

Cornish: lagas

Old Welsh: licat

Middle Welsh: lygat, llygat

Welsh: llygad

From *llugɨd (“to see, perceive”) (whence Welsh gorllwyn (“to see, perceive”)) + *-ad, from Proto-Celtic *luketi, from Proto-Indo-European *luk-é-ti (“to shine”), from *lewk- (“to shine”) + *-éti. Cognate with Latin lūcēs (“eyes”), Sanskrit लोचन (locana, “eye”).


gorθ

Old Breton: orth

Cornish: gorth

Welsh: garth

From Proto-Celtic *gortos, from Proto-Indo-European *ǵʰórtos. Cognate with Latin hortus, Old Irish gort.


ödjon

Middle Breton: egen, eugen, eugenn

Breton: ejen, ejon, ijenn

Old Cornish: odion

Middle Cornish: udzheon, odgan

Cornish: ojyon

Welsh: eidion, eidon

Fossilized plural to Proto-Celtic n-stem *otyū ~ *otyones, ultimately of uncertain origin. Perhaps related to *wedos (“yoke, harness”).


giow

Old Cornish: goiven

Cornish: gyew

Middle Welsh: giewyn sg, gieu pl

Welsh: gïau

From Proto-Celtic *gyos (reconstructed as such by McCone and Matasović; Schrijver does not specify an explicit proto-form), cognate with Ancient Greek βιός (biós, “bow-string, tendon”), Sanskrit ज्या (jyā́, “bow-string”). Proto-Celtic *gyos itself is a thematization of Proto-Indo-European *gʷyeH- (“sinew”).


hʉd

Middle Breton: hud

Middle Welsh: hud

Welsh: hud

Cornish: hus

From Proto-Celtic *soitos, or perhaps borrowed from Germanic, from Proto-Germanic *saidaz (“magic, charm”), both derivations from Proto-Indo-European *soytós.

hudol

hʉdol (“charming, illusory”) (+ *-ol); Welsh


mehalx

Old Breton: moualch

Breton: moualc'h

Old Cornish: moelh

Cornish: mola

Welsh: mwyalch, mwyeilch

Unknown. Matasović concludes it as a loanword from a Northwestern European language. Cognate with Latin merula and Proto-Germanic *amslǭ.


hoɨdl

Old Breton: hoidl

Middle Breton: hoazl

Breton: hoal

Cornish: hoedel

Middle Welsh: hoedyl

Welsh: hoedl


gwerθ

Old Breton: uuert

Middle Breton: guerz

Breton: gwerzh

Cornish: gwerth

Middle Welsh: gwerth

Welsh: gwerth

Possibly from Proto-Celtic *wertom, from Proto-Indo-European *wért-o-m, for Proto-Indo-European *wert- (“to turn”), or perhaps borrowed from Germanic, ultimately from Proto-Germanic *werþą (“worth, value”) of the same root.


gwehantuɨn

Old Cornish: guaintoin

desc

Cornish: gwenton, gwaynten (Standard Cornish)

Old Welsh: guiannuin

Middle Welsh: gwaeanhwyn

Welsh: gwanwyn

From *gwehant + *-uɨn, from Proto-Celtic *wesants (perhaps whence Gaulish simivis (“august”, literally “half-spring”)), from Proto-Indo-European *wésn-ont-s ~ *usn̥-n̥t-és (whence Sanskrit वसन्त (vasantá)), from *wós-r̥ ~ *wés-n̥s (“spring (season)”) + *-onts ~ *-n̥tés.


kuml

Breton: koumoul

Cornish: kommol

Middle Welsh: cwmwl

Welsh: cwmwl

Borrowed from Latin cumulus. The lack of lenition on the m is problematic; one would have expected *kuβ̃(u)l. GPC suggests that, like French comble, it comes from a Vulgar Latin *cumblus from *cumlus, syncopated from cumulus, and not directly from cumulus itself.


kėres

Middle Breton: queres

Breton: kerez

Cornish: keres

Welsh: ceirios

Borrowed from Late Latin ceresia, perhaps through Proto-Celtic *keresyā, from Latin cerasium.


kėfɨl

Old Breton: cefel

Breton: kefel

Old Welsh: cefel, chefel

Middle Welsh: keffyl

Welsh: ceffyl

From Proto-Celtic *kappilos, a variant form of *kaballos.


nėdr

Old Breton: natrolion pl

Middle Breton: nazr, aezr

Breton: nàer

Old Cornish: nader

Cornish: nader

Welsh: neidr

From Proto-Celtic *natrī, from Proto-Indo-European *(s)n̥H-tr-íh₂, from *(s)néHtr̥.


gwüxī

Old Breton: guohi

Middle Breton: goui

Breton: moui, boui

Old Cornish: guhi-en

Cornish: goghi

Middle Welsh: gwychi

Welsh: gwchi

→ Old Irish: foich ()
Middle Irish: foich
Irish: foiche (“wasp”)

From Proto-Celtic *woxsī, perhaps generalized from the plural, from Proto-Indo-European *wóbʰs-ih₂, variant of *wóbʰseh₂.


llaɨθ

Old Breton: laed

Middle Breton: laez

Breton: laezh

Old Cornish: lait

Middle Cornish: leth, leyth

Cornish: leth

Middle Welsh: llaeth

Welsh: llaeth

Uncertain; from earlier *llaɣθ, possibly either borrowed from Latin lacte, lac (“milk”), or inherited from Proto-Celtic *laxtos. Parallel borrowing or cognate with Old Irish lacht (“milk”).


kọs

Old Breton: cos

Middle Breton: queux

Breton: keuz

desctree

Old Cornish: cos
Middle Cornish: kez, keas
Cornish: keus

Old Welsh: caus

Middle Welsh: caws

Welsh: caws

Borrowed from Latin cāseus. Parallel borrowing with Old Irish cáise (“cheese”).


aβʉ

Middle Breton: auu

Breton: avu

Old Cornish: avi

Cornish: avi

Middle Welsh: auu

Welsh: afu

From Proto-Celtic *awV-. Cognate with Middle Irish áe.


kögin

Old Breton: covin

Breton: kegin

Old Cornish: keghin

Middle Cornish: cegin

Cornish: kegin

Middle Welsh: kegyn

Welsh: cegin

Borrowed from Late Latin cocīna (“kitchen”). Parallel borrowing to Old Irish cucann (“kitchen”).


llin

Middle Breton: lin

Cornish: lin

Welsh: llin

From Proto-Celtic *līnom. Cognate with Old Irish lín (“linen”).


llin

Middle Breton: lin

Cornish: lin

Middle Welsh: llin

From Proto-Celtic *līnom. Cognate with Old Irish lín (“full number”).


pɨsk

Middle Breton: pesq

Breton: pesk

Old Cornish: pisc

Middle Cornish: pysk

desc

Cornish: pysk, pesk (Revived Late Cornish)

Middle Welsh: pysc

q

Welsh: pysg (obsolete, displaced by the derived term pysgodyn)

Borrowed from Latin piscis. Displaced the native cognate *uɨsk (which survives only in the hydronym *Uɨsk), from Proto-Celtic *ɸeiskos (“fish”). Cognate with the inherited Old Irish íasc (“fish”).


egluɨs

Middle Breton: ylis (influenced by (Old) French eglise)

Breton: iliz

Old Cornish: eglos

Middle Cornish: eglos, egles, eglus

Cornish: eglos

Old Welsh: eccluys

Middle Welsh: eglwys, egluys

Welsh: eglwys

→ English: Eccles

Borrowed from Vulgar Latin eclēsia, from Latin ecclēsia. Parallel borrowing with Old Irish eclais (“church”).


niβ̃er

Old Breton: nimer

Middle Breton: niuer

Breton: niver

Middle Cornish: nyver, never, niver

Cornish: niver

Old Welsh: nimer

Middle Welsh: niuer, yniuer, eniuer

Welsh: nifer

Borrowed from Latin numerus. The development of the first vowel to *i is unique and has not been explained with certainty. Parallel borrowing with Old Irish nuimir (“number”).


porxell

Old Breton: porchill

Middle Breton: porchell

Breton: porc'hell

Old Cornish: porchel

Middle Cornish: porchel, porhel

Cornish: porghel, porhel

Middle Welsh: porchell

Welsh: porchell

Borrowed from Late Latin porcellus. Cognate with Proto-Celtic *ɸorkos (“pork, piglet”), both from Proto-Indo-European *pórḱos (“pig”).


estrọn

Middle Breton: estren

Breton: estren

Middle Cornish: estren

Cornish: estren

Middle Welsh: estrawn

Welsh: estron

Borrowed from Vulgar Latin *estrāneus, from Latin extrāneus.


hux

Old Breton: hoch

Middle Breton: hoc’h, houc’h

Breton: soc’h

Old Cornish: hoch

Cornish: hogh

Welsh: hwch

→? Old English: hogg (“hog”) (see there for further descendants)

From Proto-Celtic *sukkos. Doublet of *sux (“plowshare”).


funtọn

Old Breton: funtun, funton

Middle Breton: feunten, feunteun

Breton: feunteun

Old Cornish: funten

Middle Cornish: fenton, fenten, fynten

Cornish: fenten

Old Welsh: finnaun, fynnaun (nn < nt by assimilation)

Middle Welsh: fynnawn, fynhawn

Welsh: ffynnon

Borrowed from Late Latin fontāna, with regular raising of *o to *u before a nasal and stop. Compare Old English *funta, recorded in toponyms across Southern England, which in light of the vowel quality may be an early borrowing from Brythonic.


kėfɨlọg

Middle Breton: queffelec

Breton: kefeleg

Middle Cornish: kyvelak

Cornish: kevelek

Middle Welsh: cyffylog

Welsh: cyffylog

Perhaps from *kėfɨl (“horse”) + *-ọg, named for the similarity between the bird's call and the snort of a horse.


fruɨθ

Middle Breton: froez, frouez

Breton: frouezh pl

Old Cornish: fruit

→ Cornish: frooth pl (semi-learned)

Middle Welsh: ffrwyth

Welsh: ffrwyth

From earlier *fruxtos, borrowed Latin frūctus.


merθɨr

Middle Breton: merzer

Breton: merzher

Middle Cornish: *merthur (in compound)

Cornish: merther

Middle Welsh: merthyr

Welsh: merthyr

Borrowed from Latin martyr. This cannot regularly reflect an underlying, pre-apocope *martɨr (otherwise **merθr would be expected), so it is likely that the form acquired a Brythonic case ending prior to apocope (compare crux > *cruxsā > *kroɨs). Cognate with Old Irish martar. The second sense may be an independent borrowing from Ecclesiastical Latin martyrium.

(in toponyms) martyrium; burial place of a martyr


pɨskọd

Middle Breton: pesquet

Breton: pesked

Middle Cornish: puskes

Cornish: puskes, pùscas

Middle Welsh: pysgawd

Welsh: pysgod

Borrowed from Latin piscātus.
The classical usage of piscātus primarily verbal refers to the act of fishing, but as a verbal noun it developed the sense "catch, caught fish" in a collective sense. This is evidently the meaning that was carried into Proto-Brythonic, where it may have further developed a sense of "fish used as food" continued in Welsh (compare Spanish pescado for a parallel development). This plural would then have taken a regular singulative form *pɨskọdɨnn.
Subsequently, *pɨskọd was generalized as the plural of *pɨsk (“fish”) due to the appropriate grammatical number and semantics of the two terms. As a corollary, this resulted in two competing singular terms for "fish", *pɨsk and *pɨskodɨnn; the former was generalized in Breton and Cornish, while the latter became the general form in Welsh.

(possibly) food fish, fish meat used as food


traɨθ

Middle Breton: traez

Breton: traezh

Old Cornish: trait

Middle Cornish: traith, treath

Cornish: treth

Middle Welsh: traeth

Welsh: traeth

Although often supposed to be a borrowing from Latin tractus (“stretch, tract of land”) this poses semantic difficulties, and moreover the presence of an exact parallel in Old Irish tracht (“beach”) suggests instead descent from Proto-Celtic *traxtus, which could itself be from the same source as tractus (Proto-Indo-European *dʰregʰ- (“to draw out, pull”)).


haluɨn

Middle Breton: halon

Breton: halen

Old Cornish: haloin

Middle Cornish: halan, halen

Middle Welsh: halwyn, halaen, halen

Welsh: halen

From Proto-Celtic *saleinos, from Proto-Indo-European *séh₂ls (“salt”). Doublet of *heli (“brine”) and *selsig (“sausages”).


kuwann

Old Breton: couann, couhann

Middle Breton: couhenn, caouënn

Breton: kaouenn
→ Cornish: cowan

Early Vannetais Breton: cohan [1732 CE]

Vannetais Breton: kohann

Middle Welsh: cuan

From Proto-Celtic *kuwannos.
The descendants reflect dissimilation of pretonic *-uw- in differing ways. In West Brythonic this was fronted to *-ʉw-, giving Middle Welsh -u-, while in Southwest Brythonic this was lowered to *-ọw-. The latter has merged with the reflexes of Proto-Brythonic *-ow- in most dialects of Breton, but a distinction is maintained in Vannetais.


porθ

Middle Breton: porz

Breton: porzh

Old Cornish: porth

Middle Cornish: porth

Cornish: porth

Old Welsh: porth

Middle Welsh: porth

Welsh: porth (“portal”)


porθ

Middle Breton: porz

Breton: porzh

Middle Cornish: porth

Cornish: porth

Old Welsh: porth

Middle Welsh: porth

Welsh: porth (“port”)

Borrowed from Latin portus. Doublet of *rrɨd and *forð. Parallel borrowing with Old Irish port (“place, shore”).


pexọd

Middle Breton: pechet

Breton: pec’hed

Middle Cornish: peghes

⇒ Middle Cornish: pegh

Cornish: pegh

Middle Welsh: pechawt

Welsh: pechod

Borrowed from Latin peccātum. Parallel borrowing with Old Irish peccad (“sin”).


gwɨdr

Middle Breton: guezr

Breton: gwer

Middle Cornish: gweder

Cornish: gweder

Middle Welsh: gwydyr

Welsh: gwydr

Borrowed from Latin vitrum. Likely parallel borrowing with Irish fuither (“glass”).


saɣeθ

Middle Breton: saez

Breton: saezh

Middle Cornish: seth

Cornish: seth

Middle Welsh: saeth

Welsh: saeth

Borrowed from Latin sagitta. Parallel borrowing with Old Irish saiget.


dọβ̃

Middle Breton: deuff

Breton: deuñv

Old Cornish: dof

Middle Cornish: def, duf

Cornish: deuv

Old Welsh: dauu, daum
Middle Welsh: daw

From Proto-Celtic *dāmos, from Proto-Indo-European *dōm-o-s (“belonging to the house”), a vṛddhi derivative of Proto-Indo-European *dom-o-s, thematized form of *dṓm (“house, home”).
The meaning of "client" is attested only in Old Welsh, but this sense is likely to be inherited based on the Old Irish cognate dám (“company, retinue”).


plʉβ̃

head

*plʉβ̃ m pl or f pl (singulative *plʉβ̃ɨnn, *plʉβ̃enn)

plʉβ̃ɨnn (singulative)
plʉβ̃enn (singulative)

Old Breton: *plum

Middle Breton: pluff

Breton: pluñv

Old Cornish: *pluf

Middle Cornish: pluv, plyv

Cornish: pluv

Old Welsh: *plum

Middle Welsh: plu, plvf

Welsh: plu, pluf

Borrowed from Latin plūma (“feather, plume”). Parallel borrowing with Old Irish clúm (“feathers”).


plʉβ̃ọg

Old Breton: plumoc

Middle Breton: pluffec

Breton: pluñveg

Old Cornish: plufoc

→ Cornish: pluvek (semi-learned)

Old Welsh: plumauc

>? Welsh: pluog (possibly re-coined in Modern Welsh)


Sėɨs

*Sėɨs m (feminine *Saɨsnes, plural *Saɨson)

Middle Breton: Saus

Breton: Saoz

Cumbric:

→ English: Pennersax

Middle Cornish: *Seys (attested in personal name)

Cornish: Sows

Middle Welsh: Seis

Welsh: Sais

From earlier *Saxsī, borrowed from Latin Saxō, itself borrowed from Proto-West Germanic *sahsō. Parallel borrowing with Middle Irish Saxa.


Saɨson

Middle Breton: Saoson

Breton: Saozon

Middle Welsh: Saesson

Welsh: Saeson

From earlier *Saxsones, the regular plural of the n-stem *Saxsī. Not directly from Latin Saxōnēs, as this would instead have resulted in **Saɨsʉn.


lleɣenn

Middle Breton: lenn, leenn

desc

⇒ Middle Breton: lenn, leenn (“to read”)

Breton: lenn

Middle Cornish: lyen

Cornish: lien

Middle Welsh: lleen, llen

Welsh: llên

Borrowed from Latin legendum, legendā. Parallel borrowing with Old Irish léigenn (“studying, learning”).


brėx

Middle Breton: brech

Breton: brec'h

Old Cornish: brech

Middle Cornish: bregh

Cornish: bregh

Middle Welsh: breich

Welsh: braich

Borrowed from Latin bracchium. Parallel borrowing with Irish brac (“arm”).


kawl

Middle Breton: caul pl, caoll pl

Breton: kaol pl

Old Cornish: caul

→ Cornish: kowl (semi-learned)

Middle Welsh: kawl

Welsh: cawl
→ English: cawl

Borrowed from Latin caulis. Parallel borrowing with Irish cóilis (“cabbage”).


kantuɨll

Middle Breton: cantoell

Breton: kantol

Old Cornish: cantuil

Middle Cornish: kantyll

Cornish: kantl

Middle Welsh: canhwyll

Welsh: cannwyll

Borrowed from Vulgar Latin *cantēlla, *cantēla, from Latin candēla. Parallel borrowing with Old Irish caindel.


gwenuɨn

Old Cornish: *guenoin

⇒ Old Cornish: guenoin-reiat

Middle Welsh: gwenwyn

Welsh: gwenwyn


paraduɨs

Middle Breton: paradoes, barados, barazoes, baradoes

Breton: baradoz, paradoez, baraouiz (Gwenedeg)

Middle Cornish: parathys, paradys

Cornish: paradhis

Middle Welsh: paradwys

Welsh: paradwys

Borrowed from Vulgar Latin *paradēsus, from Latin paradīsus. Parallel borrowing with Middle Irish pardus (“paradise”).


kaduɨr

Middle Breton: cadoer

Breton: kador

Middle Cornish: *gadoer

Cornish: cadar

⇒ Middle Cornish: Pengadoer

Middle Welsh: cadeir

Welsh: cadair

Borrowed from Latin cathedra. Distantly related Proto-Brythonic *heðɨd (“to sit”), *nɨθ (“nest”). Parallel borrowing with Old Irish cathaír (“chair”).


pluɨβ

Breton: ploue

Cornish: pluw

Middle Welsh: plwyf

Welsh: plwyf

Borrowed from Latin plēbēs (“common people”).


spɨrɨd

Breton: spered

Middle Cornish: sperys

Cornish: spyrys

Middle Welsh: yspryt

Welsh: ysbryd

Borrowed from Latin spīritus. Parallel borrowing with Old Irish spirut (“spirit”).


rruɨd

Breton: roued

Old Cornish: ruid

Cornish: roos

Middle Welsh: rwyd

Welsh: rhwyd


manax

Breton: manac'h

Old Cornish: manach

Cornish: manah

Middle Welsh: manach, menach

Welsh: mynach

→? Old Irish: manach (see there for further descendants)

Borrowed from Latin monachus. Parallel borrowing with Old Irish manach.


meβ̃or

Old Breton: memor

Breton: eñvor (doublet with memor)

Middle Cornish: myfyr

Borrowed from Latin memoria. Parallel borrowing with Old Irish mebuir (“recollection, memory”).


kluɨreg

Breton: kloarek

Old Cornish: cloireg

Cornish: klorek

Borrowed from Latin clēricus. Parallel borrowing with Welsh clerig (“cleric”), Old Irish clérech (“cleric, clerk, scholar”).


rruɨβ̃

Middle Breton: reuff, roeuff

Breton: roeñv

Old Cornish: ruif

Cornish: rev

Middle Welsh: rwyf

Welsh: rhwyf

Borrowed from Latin rēmus. Doublet of *rrọβ (“shovel, spade”), cognate with Old Irish rámae (“oar, spade”).


skuβarn

Old Breton: *scobarn (in compound)

Middle Breton: scouarn

Breton: skouarn

Old Cornish: scouarn

desc

Middle Cornish: scovern, scovorn, scoforn

Cornish: skovarn

Middle Welsh: ysgyuarn, hyscyfarn

Welsh: ysgyfarn

Unknown. The first element may ultimately be derived from Proto-Indo-European *(s)kewh₁- (“to observe, perceive”).


skuβarnọg

Middle Breton: scouarnec

Breton: skouarneg

Old Cornish: scouarnoc

Cornish: skovarnek

→ English: scavernick

Middle Welsh: yscyfarnawc, ysgyuarnauc

Welsh: ysgyfarnog


gwuɨl

Breton: gouel

Cornish: goel

Middle Welsh: gwyl

Welsh: gŵyl

From earlier *gwēl, from *gwɨɣl, borrowed from Vulgar Latin viglia, from Latin vigilia (“watch, vigil”). Parallel borrowing with Old Irish féil (“festival, feast day”), Middle Irish figel, figell (“vigil”).


gwuɨl

Breton: gouel

Middle Cornish: goyl

Borrowed from Latin vēlum (“curtain, veil; sail of a ship”). Parallel borrowing with Old Irish fíal (“veil, curtain”).


arxangel

Middle Breton: archael

Breton: arc'hael

Old Cornish: archail

Middle Welsh: archangel

Welsh: archangel

Borrowed from Latin archangelus. Parallel borrowing with Old Irish arc(h)aingel.


kuɨr

Breton: koar

Old Cornish: coir

Cornish: kor

Middle Welsh: cwyr

Welsh: cwyr

Borrowed from Latin cēra (“wax”). Parallel borrowing with Old Irish céir (“wax”).


kuɨn

Breton: koan

Cornish: cean

Middle Welsh: cwyn


bʉal

Middle Breton: bual

Breton: bual

Cornish: bual

Middle Welsh: bual

Welsh: bual

Borrowed from Latin būbalus (“buffalo, antelope”). Parallel borrowing with Old Irish búaball (“buffalo”).


hüβol

Middle Breton: hual

Breton: hual, fuul

Old Welsh: fual

Middle Welsh: hual

Welsh: hual, (obsolete) fuul

From earlier *hwiβol, borrowed from Vulgar Latin fĭbula, from Latin fībula (“clasp, buckle, fetter”). Parallel borrowing with Old Irish sibal, siball (“clasp, buckle”).


gwesper

Breton: gousper, gosper, guesper

Cornish: gwesper

Middle Welsh: gosper

Welsh: gosber

PIE word
 *wek(ʷ)speros
Borrowed from Latin vesper (“evening, vesper”). Doublet of *ʉxer (“evening”). Possible parallel borrowing with Old Irish fescor (“evening, vesper”), if not inherited from Proto-Celtic *weskʷeros.


geβ̃ell

Breton: gevell

Cornish: gevell, gevelles

Middle Welsh: gefell, geuell

Welsh: gefell, gefeilles

Borrowed from Latin gemellus (“twin”). Proto-Celtic doublet with *yemonos (“twin”), whence Old Irish emon.


tuɨg

Breton: toag

Old Welsh: tuic

Middle Welsh: twyg

Welsh: twyg

Borrowed from Latin thēca (“a case, envelope, sheath”). Parallel borrowing with Old Irish tíag (“wallet, satchel”), and Irish tiach (“theca”).


suɨβ̃

Middle Breton: soaff, soa

Breton: soav

Middle Cornish: soa

Cornish: soov

Middle Welsh: swyf

Welsh: swyf

Borrowed from Latin sēbum (“tallow, grease”). Parallel borrowing with Irish saim (“lard”), Cornish seym, and Welsh saim, all through Old French saim (“fat”).


arọd

Middle Breton: euret

Breton: eured

Cornish: areth

Middle Welsh: arawt

→ Old Irish: oráit

Borrowed from Vulgar Latin *arātiō, from Latin ōrātiō (“speech; prayer”).


pexadʉr

Middle Breton: pechezr

Breton: pec'her

Middle Cornish: pechadur, pehadur

Cornish: peghador

Middle Welsh: pechadur

Welsh: pechadur

Borrowed from Vulgar Latin peccătōrem, from Latin peccātōrem with pretonic shortening of ā. Equivalent to *pexọd (“sin”) or *pexad (“to sin”) + *-adʉr.


pexọdow

Middle Breton: pechedou

Breton: pec'hedoù

Middle Cornish: peghosow, peghusow

Middle Welsh: pechodeu

Welsh: pechodau


streɨl

Old Cornish: streil

Cornish: streil

From earlier *streɣl, borrowed from Vulgar Latin *strigla, from Latin strigula, strigilis (“strigil”).


maguɨr

Old Breton: macoer

Breton: moger, magoar

Middle Welsh: magwyr

Welsh: magwyr

Borrowed from Vulgar Latin măcēria, from Latin mācĕria (“wall”). Parallel borrowing with Middle Irish macre (“wall trowel”).


aβuɨn

Cornish: avond

Middle Welsh: afwyn

Welsh: awen

Borrowed from Latin habēna (“thong, rein, lash, bridle”). Related to *gaβl (“fork”). Parallel borrowing with Middle Irish abann (“scourge, whip”).


strodʉr

Old Welsh: strotur

Middle Welsh: estrodur

Welsh: ystrodur

Borrowed from Vulgar Latin strătūra, from Latin strātūra (“saddle”). Parallel borrowing with Old Irish srathar (“pack-saddle”).


kʉβɨgl

Middle Welsh: kudygyl

Welsh: cuddygl, cufygl (doublet with ciwbicl)

Borrowed from Latin cubīclum, cubiculum (“small bedroom; bedchamber”). Parallel borrowing with Middle Irish cubachail (“cubicle, small bedchamber”).


paruɨd

Old Cornish: poruit

Middle Welsh: parwyt, paraet, paret

Welsh: pared

Borrowed from Late Latin parēs (“wall”).


mėnɨβr

Welsh: menebyr, menybyr, mynebr, mynyhr

Borrowed from Latin manĭbrium, manūbrium (“handle, haft”).


neɨθjọr

Middle Welsh: neithiawr

Welsh: neithiawr

From earlier *nexθjọr, borrowed from Latin nūptiālia (“wedding feast”).


munβ̃ent

Middle Welsh: mynwent

Welsh: mynwent

Borrowed from Latin monumenta, nominative plural of monumentum (“memorial, monument, tomb”). Cognate with *menw (“thought, mind”). Parallel borrowing with Middle Irish monameint (“monument”).


menw

Middle Breton: meno

Breton: meno

Middle Welsh: mynw


korruɨ

desc

Middle Breton: *correu (plural), correenn (singulative)

Old Welsh: corruui

Middle Welsh: carryeu, carreieu, carrei, carei

Welsh: carrai

Disputed; possibly either:
* borrowed from Latin corrigia, conrigia (“shoe-string; whip-lash, rein”), perhaps through Vulgar Latin *correia, if not itself borrowed from Celtic;
* or inherited from Proto-Celtic *kom-ɸro-rig-ā, from *kom- (“with”) + *ɸro- (“before”) + *rigeti (“to bind”) + *-ā.


gwɨrθ

Old Welsh: guirdou pl

Middle Welsh: guirth, gwyrth

Welsh: gwyrth

Borrowed from Latin virtūs (“manhood, virtue”). Cognate with *gwur (“man, husband”). Parallel borrowing with Old Irish firtu (“miracle”), and perhaps Gaulish *uiridos, attested in various personal names.


axọs

Middle Welsh: achaws

Welsh: achos

Borrowed from Latin occāsiō (“occasion, opportunity”). Parallel borrowing with Cornish acheson (“occasion, reason”), Old Irish accuis (“cause, reason”).


trindọd

Breton: trinded

desc

Cornish: trindas, trinsys, trengys, trenses

Old Welsh: trintaut

Middle Welsh: trindawt, trindod

Welsh: trindod

→ Old Irish: tríndóit

Irish: trindaid

Manx: trinaid

Scottish Gaelic: trionaid, trianaid

Borrowed from Latin trīnitātem, accusative singular of trīnitās (“Trinity”).


bendiθ

Middle Breton: bennoz, bennoez

Breton: bennozh

Middle Cornish: bennath, benneth

Cornish: bednath

Middle Welsh: bendith

Welsh: bendith

From earlier *bendɨxθ, borrowed from Latin benedictiō, benedictum (“blessing, benediction”). Parallel borrowing with Old Irish bendacht (“blessing, benediction”).


eβengɨl

Breton: aviel

Old Cornish: aweil

Middle Cornish: awayl

Cornish: aweyl

Middle Welsh: euegyl, *efengyll

Welsh: efengyl, efangel, efangyl

Borrowed from Latin evangelium (“gospel”), itself borrowed from Ancient Greek εὐαγγέλιον (euangélion, “bringing good news”), from εὐ- (eu-, “good”) + ἄγγελος (ángelos, “messenger”), equivalent to *hu- (“good”) + *angel (“angel, messenger (of God)”). Old Irish adopted the calque soiscélae, from so- (“good”) + scél (“news”).


dinėr

Breton: diner

desc

Cornish: dinair, dinar, diner, dynar, dyner, dynnar

Welsh: dinair

Borrowed from Vulgar Latin dēnărius, from Latin dēnārius (“denary”).


profuɨd

Breton: profed

Cornish: profus, profuit

Welsh: proffwyd

Borrowed from Latin prophēta (“prophet”).


tɨner

Breton: tener

Middle Welsh: tyner

Welsh: tyner

Borrowed from Latin tener (“soft, tender, delicate”). Parallel borrowing with Cornish tender (“sensitive, tender”).


ọr

Old Breton: or

Middle Breton: eur

Breton: eur

Cornish: eur

Old Welsh: aur

Middle Welsh: awr

Welsh: awr

Borrowed from Latin hōra (“hour”). Parallel borrowing with Old Irish úar, úair (“hour”).


abrant

Breton: abrant

Cornish: abrans

Middle Welsh: amrant

Welsh: amrant


lloβ̃an

Middle Breton: louffan

Breton: louan

Cornish: lovan

Middle Welsh: llyfan

Welsh: llyfan


taβern

Breton: tavarn

Cornish: tavern

Middle Welsh: tauarn

Welsh: tafarn

Borrowed from Latin taberna (“inn”). Parallel borrowing with Irish tábhairne (“tavern”).


ʉxer

Old Cornish: *uher

⇒ Old Cornish: gurthuher

Cornish: gorthugher

Middle Welsh: ucher, uchyr

Welsh: ucher

From earlier *wixer, from Proto-Celtic *weskʷeros. Doublet of *gwesper (“evening”).


exuɨð

Breton: ec'hoaz

Cornish: ewhe

Welsh: echwydd

From earlier *ekkēdos or similar, of unknown origin; possibly related to Old Irish adaig (“night”), from earlier *adek(ʷ)ī, whose etymology is also obscure.


henoɨθ

Middle Breton: hanoez

Breton: henoazh

Middle Cornish: haneth

Old Welsh: henoid

Middle Welsh: heno

Welsh: heno


ʉθ

Middle Breton: euz

Breton: euzh

Cornish: uth, euth

Welsh: uthr

From Proto-Celtic *(ɸ)owtus, *awtus, possibly related to *oβn (“fear”). Cognate with Old Irish úath (“hate”).


oβn

Middle Breton: oun

Breton: ovn

Cornish: own

Middle Welsh: ofuyn

Welsh: ofn

From Proto-Celtic *(ɸ)oβnus, possibly related to *ʉθ (“horror”). Cognate with Old Irish ómun (“fear”).


llenn

Old Breton: lenn

Breton: lenn

Old Cornish: len

Cornish: len

Old Welsh: lenn

Middle Welsh: llen

Welsh: llen

From Proto-Celtic *linnā. Cognate with Old Irish lenn (“cloak”).


diaβul

Middle Breton: diaoul

Breton: diaoul

Cornish: dyowl, dyaul, jawl

Old Welsh: diaul

Middle Welsh: diawl, diauul

Welsh: diawl, diafol

Borrowed from Latin diabolus. Parallel borrowing with Old Irish díabul (“devil”).


kiwdọd

Middle Breton: queudet

Breton: keoded

Middle Welsh: kiwdawt

Welsh: ciwdod

Borrowed from Vulgar Latin *[kiwˈtate~kiβˈtate], from Latin cīvitātem, accusative singular of cīvitās (“citizenry; city”). Doublet of *kiwed, from the nominative singular, whence Welsh ciwed.


llɨβr

Old Breton: libr

Middle Breton: leor

Breton: levr

Middle Cornish: lyver

Cornish: lyver

Middle Welsh: llyuyr

Welsh: llyfr

Borrowed from Vulgar Latin lĭbrum, from Latin lībrum, accusative singular of līber (“book”). Parallel borrowing with Old Irish lebor (“book”).


tɨɣern

Old Breton: *tiarn, *tiern

Middle Breton: tiern

Breton: tiern

Old Welsh: *tigern

Middle Welsh: teern, teyrn

Welsh: teyrn

From Proto-Celtic *tigernos. Cognate with Old Irish tigern (“lord”).


gwolʉd

Middle Welsh: golud

Welsh: golud

From Proto-Celtic *uɸolautom (“wealth, property”). Cognate with Old Irish folud (“wealth”).


eðenn

Middle Breton: ilieavenn

Breton: iliav, ilio, iliavenn (sgv.)

Cornish: idhyow, idhyo, idhyowen (sgv.)

Middle Welsh: eido, eiddio

Welsh: eiddew, eiddo

From Proto-Celtic *edennos. Cognate with Old Irish eidenn (“ivy”).


eβur

Middle Breton: heuor, euor

Breton: evor (“alder buckthorn”)

Cornish: evor (“hogweed”)

Middle Welsh: efwr, ewr

Welsh: efwr (“hogweed, cow parsnip”)

From Proto-Celtic *eburos (“yew”). Cognate with Old Irish ibar (“yew”).

The meaning of this term is uncertain. Possibilities include: yew, cow parsnip, hogweed, buckthorn


lluss

Middle Breton: lousaou pl

Breton: louzoù

Old Cornish: les

Middle Cornish: leys sg, losow pl

Cornish: les sg, losow pl

Middle Welsh: llysyeu pl

Welsh: llys sg, llysiau, llysau pl


dexowluss

Middle Breton: dehoules

Welsh: deheulys

From *dexow (“southern”) + *lluss (“herb”). Possible calque of Old English sūþernewudu (“southernwood, wormwood”).


bux

Middle Breton: bouch

Breton: bouc'h

Old Cornish: boch

Middle Welsh: bwch

Welsh: bwch


bʉ

Breton: bu

Middle Welsh: bu, buw


bʉx

Breton: buoc’h

Old Cornish: buch

Middle Cornish: bugh

Cornish: bugh

Middle Welsh: buch

Welsh: buwch

Modified from *bʉ (“cow”) under the influence of other animal names ending with *-x, such as *bux (“goat”), *hux (“pig”), *mox (“pigs”).


kunikl

Middle Breton: conicl, conniffl

Breton: konikl, konifl


pɨg

Old Breton: pic

Middle Breton: pec

Breton: pec, peg

Welsh: pyg

Cornish: peg

Borrowed from Latin pix. Parallel borrowing with Irish pic (“pitch, tar”).


skudell

Breton: skudell

Cornish: skudel

Welsh: ysgudell


ʉβ̃ɨldọd

Middle Breton: uveltet

Breton: uvelded

Old Cornish: huveldot

Old Welsh: uvyltavd

Middle Welsh: uvildaud, uvylltawd

Welsh: ufylltod, ufulltod

Borrowed from Latin humilitātem. Parallel borrowing with Old Irish humaldóit, umaldóit (“humility”).


koluɨn

Breton: kolen

Old Cornish: coloin

Cornish: kolen

Welsh: colwyn

From Proto-Celtic *kolignos, possibly of non-Indo-European origin.


brọdr

Old Breton: brotr

Middle Breton: breuzr

Breton: breur

Old Welsh: braut

Welsh: brawd

Cornish: broder

From Proto-Celtic *brātīr. The loss of the -ī- in the singular is regular.


Prɨdėn

Possibly from Proto-Indo-European *kʷer- (“to do”).


marxad

Old Breton: marchat

Middle Breton: marchat

Breton: marc'had

Middle Cornish: marghas

Cornish: marghas

Borrowed from Vulgar Latin marcatus, from Late Latin marcātus, from Latin mercātus.


skʉbọr

q

attested in the place name <i class="Latn mention" lang="xbm">Squiber Nevez</i>

Middle Breton: *squiber (attested in the place name Squiber Nevez)

Breton: skiber

Middle Cornish: skyber

Cornish: skiber

Old Welsh: scipaur

Middle Welsh: yscubawr

Welsh: ysgubor, sgubor

→ Irish: scioból

From British Latin *scōpārium, from scōpa (“branch, sheaf”).


furn

Old Cornish: forn

→ Cornish: forn

Middle Breton: forn

Middle Welsh: ffwrn

Welsh: ffwrn

desctree

→ Old Irish: sorn, sornn
Irish: sorn
Manx: sorn
Scottish Gaelic: sòrn
→ Faroese: sornur
→ Norwegian Nynorsk: sonn


llɨθer

Middle Breton: lizer

Breton: lizher

Middle Cornish: lyther

Cornish: lyther

Old Welsh: leder

Middle Welsh: llythyr

Welsh: llythyr

letter (symbol in an alphabet; written or printed communication)


auɨr

Middle Welsh: awyr

From Latin āēr, from Ancient Greek ᾱ̓ήρ (āḗr, “wind, atmosphere”).


aðʉrn

Middle Welsh: aðurn


ankow

Middle Welsh: angheu


arβ̃

Middle Cornish: arvov pl

Middle Welsh: arf, aryf
Welsh: arf


brėsɨx

Middle Welsh: bressych


ėɣɨft

Middle Welsh: Eifft


kɨlx

Breton: kelc'h

Cornish: kylgh

Middle Welsh: kylch

Welsh: cylch

The connection between this word and Old Welsh circhl (from Proto-Brythonic *kɨrxl, from Latin circulus) is unclear; perhaps there was metathesis of the r and l to *kɨlxr followed by cluster simplification to *kɨlx. The fact that both Breton and Welsh show reflexes of *kɨlx means that such a change must have happened before Proto-Brythonic broke up into its daughter languages, in which case Old Welsh circhl would reflect either an unaltered byform existing alongside the altered form or a reborrowing from the Latin.
A possibility mentioned by Morris Jones is that *kɨlx is inherited from Proto-Indo-European *kuklós (with metathesis of kl to lk > lx) and thus cognate with Ancient Greek κύκλος (kúklos), Old English hwēol and Sanskrit चक्र (cakra).
A third possibility is that *kɨlx could be borrowed (still with metathesis) from Latin cyclus, from Ancient Greek κύκλος (kúklos).


heð

Old Breton: hed

Middle Breton: hez

Breton: hez

Middle Welsh: hedd

Welsh: hedd


üx

Old Breton: ohen

Middle Breton: ouhen

Breton: oc'hen

Old Cornish: oghan, ohan

Cornish: oghen pl

Middle Welsh: ychen sg (“ox”), ych pl

Welsh: ych sg, ychain pl


tirjon

Middle Breton: tyryen

desc

Breton: tirien, tirion (“wasteland, fallow land; lawn; upper part of a meadow where the earth is dry”)

Middle Welsh: tirion (“lands?; territory, plain, grassland”)

Fossilized plural to Proto-Celtic *tīryū ~ *tīryones, n-stem to *tir (“land”).