"esse" meaning in Old Irish

{
  "head_templates": [
    {
      "args": {
        "1": "sga",
        "2": "prepositional pronoun"
      },
      "expansion": "esse",
      "name": "head"
    }
  ],
  "lang": "Old Irish",
  "lang_code": "sga",
  "pos": "pron",
  "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": "Old Irish prepositional pronouns",
          "parents": [
            "Prepositional pronouns",
            "Prepositions",
            "Pronoun forms",
            "Lemmas",
            "Non-lemma forms",
            "Pronouns"
          ],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "as"
        }
      ],
      "glosses": [
        "third-person singular feminine of as"
      ],
      "id": "en-esse-sga-pron-p5DuCEh2",
      "links": [
        [
          "as",
          "as#Old Irish"
        ]
      ],
      "synonyms": [
        {
          "word": "essi"
        },
        {
          "word": "eissi"
        }
      ],
      "tags": [
        "feminine",
        "form-of",
        "singular",
        "third-person"
      ]
    }
  ],
  "word": "esse"
}

{
  "head_templates": [
    {
      "args": {
        "1": "sga",
        "2": "prepositional pronoun"
      },
      "expansion": "esse",
      "name": "head"
    }
  ],
  "lang": "Old Irish",
  "lang_code": "sga",
  "pos": "pron",
  "senses": [
    {
      "categories": [
        "Old Irish entries with incorrect language header",
        "Old Irish non-lemma forms",
        "Old Irish palindromes",
        "Old Irish prepositional pronouns"
      ],
      "form_of": [
        {
          "word": "as"
        }
      ],
      "glosses": [
        "third-person singular feminine of as"
      ],
      "links": [
        [
          "as",
          "as#Old Irish"
        ]
      ],
      "tags": [
        "feminine",
        "form-of",
        "singular",
        "third-person"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "essi"
    },
    {
      "word": "eissi"
    }
  ],
  "word": "esse"
}