"-iu" meaning in Old Irish

{
  "descendants": [
    {
      "depth": 1,
      "templates": [
        {
          "args": {
            "1": "mga",
            "2": "-iu"
          },
          "expansion": "Middle Irish: -iu",
          "name": "desc"
        }
      ],
      "text": "Middle Irish: -iu"
    },
    {
      "depth": 2,
      "templates": [
        {
          "args": {
            "1": "ga",
            "2": "-e",
            "id": "comparative"
          },
          "expansion": "Irish: -e",
          "name": "desc"
        }
      ],
      "text": "Irish: -e"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "sga",
        "2": "cel-pro",
        "3": "*-yūs"
      },
      "expansion": "Proto-Celtic *-yūs",
      "name": "inh"
    },
    {
      "args": {
        "1": "sga",
        "2": "ine-pro",
        "3": "*-yōs"
      },
      "expansion": "Proto-Indo-European *-yōs",
      "name": "inh"
    }
  ],
  "etymology_text": "From Proto-Celtic *-yūs, from Proto-Indo-European *-yōs.",
  "head_templates": [
    {
      "args": {
        "1": "sga",
        "2": "suffix",
        "cat2": "inflectional suffixes"
      },
      "expansion": "-iu",
      "name": "head"
    }
  ],
  "lang": "Old Irish",
  "lang_code": "sga",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Old Irish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages using catfix",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 3 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "sen (“old”) + -iu → siniu (“older”)",
          "type": "example"
        },
        {
          "text": "oll (“ample”) + -iu → uilliu (“more ample”)",
          "type": "example"
        },
        {
          "text": "dían (“swift”) + -iu → déniu (“swifter”)",
          "type": "example"
        },
        {
          "text": "tiug (“thick”) + -iu → tigiu (“thick”)",
          "type": "example"
        },
        {
          "text": "tanae (“thin”) + -iu → tanu (“thinner”)",
          "type": "example"
        },
        {
          "text": "lobur (“weak”) + -iu → lobru (“weaker”)",
          "type": "example"
        }
      ],
      "glosses": [
        "Used to form the comparative degree of adjectives -er, more (if possible it palatalises the preceding consonant and raises preceding vowel)"
      ],
      "id": "en--iu-sga-suffix-l0AVXrvW",
      "links": [
        [
          "-er",
          "-er"
        ],
        [
          "more",
          "more"
        ]
      ],
      "synonyms": [
        {
          "english": "when the preceding consonant (cluster) isn't palatalised",
          "word": "-u"
        },
        {
          "english": "in irregular comparatives",
          "word": "-a"
        }
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[u]"
    }
  ],
  "word": "-iu"
}

{
  "descendants": [
    {
      "depth": 1,
      "templates": [
        {
          "args": {
            "1": "mga",
            "2": "-iu"
          },
          "expansion": "Middle Irish: -iu",
          "name": "desc"
        }
      ],
      "text": "Middle Irish: -iu"
    },
    {
      "depth": 2,
      "templates": [
        {
          "args": {
            "1": "ga",
            "2": "-e",
            "id": "comparative"
          },
          "expansion": "Irish: -e",
          "name": "desc"
        }
      ],
      "text": "Irish: -e"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "sga",
        "2": "cel-pro",
        "3": "*-yūs"
      },
      "expansion": "Proto-Celtic *-yūs",
      "name": "inh"
    },
    {
      "args": {
        "1": "sga",
        "2": "ine-pro",
        "3": "*-yōs"
      },
      "expansion": "Proto-Indo-European *-yōs",
      "name": "inh"
    }
  ],
  "etymology_text": "From Proto-Celtic *-yūs, from Proto-Indo-European *-yōs.",
  "head_templates": [
    {
      "args": {
        "1": "sga",
        "2": "suffix",
        "cat2": "inflectional suffixes"
      },
      "expansion": "-iu",
      "name": "head"
    }
  ],
  "lang": "Old Irish",
  "lang_code": "sga",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        "Old Irish entries with incorrect language header",
        "Old Irish inflectional suffixes",
        "Old Irish lemmas",
        "Old Irish suffixes",
        "Old Irish terms derived from Proto-Celtic",
        "Old Irish terms derived from Proto-Indo-European",
        "Old Irish terms inherited from Proto-Celtic",
        "Old Irish terms inherited from Proto-Indo-European",
        "Pages using catfix",
        "Pages with 3 entries",
        "Pages with entries"
      ],
      "examples": [
        {
          "text": "sen (“old”) + -iu → siniu (“older”)",
          "type": "example"
        },
        {
          "text": "oll (“ample”) + -iu → uilliu (“more ample”)",
          "type": "example"
        },
        {
          "text": "dían (“swift”) + -iu → déniu (“swifter”)",
          "type": "example"
        },
        {
          "text": "tiug (“thick”) + -iu → tigiu (“thick”)",
          "type": "example"
        },
        {
          "text": "tanae (“thin”) + -iu → tanu (“thinner”)",
          "type": "example"
        },
        {
          "text": "lobur (“weak”) + -iu → lobru (“weaker”)",
          "type": "example"
        }
      ],
      "glosses": [
        "Used to form the comparative degree of adjectives -er, more (if possible it palatalises the preceding consonant and raises preceding vowel)"
      ],
      "links": [
        [
          "-er",
          "-er"
        ],
        [
          "more",
          "more"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[u]"
    }
  ],
  "synonyms": [
    {
      "english": "when the preceding consonant (cluster) isn't palatalised",
      "word": "-u"
    },
    {
      "english": "in irregular comparatives",
      "word": "-a"
    }
  ],
  "word": "-iu"
}