Lao

From Latin Laus, from Ancient Greek Λαός (Laós), likely ultimately from Proto-Indo-European *lewh₃- (“to wash”), common in hydronyms. The first vowel may have derived from an O-grade or from the zero-grade, depending on the language it was borrowed through.


Ticino

Ticino (a left tributary of the Po in Switzerland and Italy)


Po

Ultimately from Latin Padus, perhaps borrowed in this form from some Gallo-Italic variety to judge by the loss of /-d-/. On the other hand, should one assume that said loss occurred (irregularly) in Tuscany, the sound-changes from that point onward would be fairly straightforward: /ˈpa.o/ > /ˈpaw/ > /ˈpɔ/.


Stella

Friuli-Venezia Giulia
Friuli-Venezia Giulia#English


Adige

From Latin Athesem, presumably borrowed via Gallo-Italic.


Acquacheta

Acquacheta (a river that flows through Tuscany and Emilia-Romagna, Italy)


Piave

a river in Veneto that was the scene of heavy fighting in World War I


Adda

a tributary of the river Po in northern Italy


Isarco

Trentino-Alto Adige
Trentino-Alto Adige#English


Enza

Borrowed from Emilian, from Latin Incia.
The given name is Enzo + -a, ultimately of Germanic origin.


Chiese

From Latin Clesis, variation of Clūsius.


Dora Riparia

From Latin Duria. "Riparia" comes from Ripa, the name of an affluent, and it's used to distinguish this river from the Dora Baltea.


Simeto

From Latin Symaethus, from Ancient Greek Σύμαιθος (Súmaithos).


Alcantara

Borrowed from Arabic اَلْقَنْطَرَة (al-qanṭara, “the bridge”).

bor+

اَلْقَنْطَرَة


Anapo

From Latin Anapus, from Ancient Greek Ἄναπος (Ánapos).


Ciane

From Latin Cyane, from Ancient Greek Κυάνη (Kuánē).


Ippari

From Latin Hipparis, from Ancient Greek Ἵππαρις (Hípparis).


Naro

Disputed. Theorized origins include:
* Ancient Greek ναρόν (narón, “current”)
* Ancient Greek νηρόν (nērón) / νερόν (nerón), both meaning "water"
* Arabic نَهَر (nahar, “river”)


Imera

From Latin Himera, from Ancient Greek Ἱμέρα (Himéra).


Tirso

From Latin Thyrsus, from Ancient Greek Θύρσος (Thúrsos).


Soligo

a river in Veneto, from the name of the village it crosses


Miscano

From the earlier form Misclanu (attested since 10th century). Further etymology unknown.


Corno

From corno, because of the shape of its course.


Clitunno

a small river in Umbria, famous for its springs


Dittaino

From Arabic وَادِي التِين (wādī t-tīn, literally “clay river”).

uder

وَادِي التِين


Gornalunga

Italianized after Sicilian Gurnalonga, from gurna (small body of water) + longa (long).


Farfa

From Latin Farfarus, another name of the river Fabaris.


Mazaro

From Latin Mazarus, alternative form of Mazara.


Bagni

Bagni (a stream in Lamezia Terme, Catanzaro, Calabria, Italy)