"n-esséirgu" meaning in Old Irish

{
  "head_templates": [
    {
      "args": {
        "1": "sga",
        "2": "mutated noun"
      },
      "expansion": "n-esséirgu",
      "name": "head"
    }
  ],
  "lang": "Old Irish",
  "lang_code": "sga",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "esséirgu"
        }
      ],
      "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 with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Eclipsed form of esséirgu."
      ],
      "id": "en-n-esséirgu-sga-noun-c0AU4BdJ",
      "links": [
        [
          "esséirgu",
          "esséirgu#Old_Irish"
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "eclipsis"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈn͈ʲesʲeːrʲɣʲu]"
    }
  ],
  "word": "n-esséirgu"
}

{
  "head_templates": [
    {
      "args": {
        "1": "sga",
        "2": "mutated noun"
      },
      "expansion": "n-esséirgu",
      "name": "head"
    }
  ],
  "lang": "Old Irish",
  "lang_code": "sga",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "esséirgu"
        }
      ],
      "categories": [
        "Old Irish eclipsed forms",
        "Old Irish entries with incorrect language header",
        "Old Irish mutated nouns",
        "Old Irish non-lemma forms",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "Eclipsed form of esséirgu."
      ],
      "links": [
        [
          "esséirgu",
          "esséirgu#Old_Irish"
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "eclipsis"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈn͈ʲesʲeːrʲɣʲu]"
    }
  ],
  "word": "n-esséirgu"
}