"a." meaning in Translingual

{
  "etymology_templates": [
    {
      "args": {
        "1": "mul",
        "2": "la",
        "3": "artēria",
        "t": "artery"
      },
      "expansion": "Latin artēria (“artery”)",
      "name": "der"
    },
    {
      "args": {
        "1": "mul",
        "2": "Latin <i class=\"Latn mention\" lang=\"la\">artēria</i> (“artery”)"
      },
      "expansion": "Abbreviation of Latin artēria (“artery”)",
      "name": "abbrev"
    }
  ],
  "etymology_text": "Abbreviation of Latin artēria (“artery”).",
  "forms": [
    {
      "form": "aa.",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "noun",
        "3": "plural",
        "4": "aa."
      },
      "expansion": "a. (plural aa.)",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Translingual entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "mul",
          "name": "Medicine",
          "orig": "mul:Medicine",
          "parents": [
            "Biology",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "artery"
      ],
      "id": "en-a.-mul-noun-ojRefDqu",
      "links": [
        [
          "medicine",
          "medicine"
        ],
        [
          "artery",
          "artery"
        ]
      ],
      "raw_glosses": [
        "(medicine) artery"
      ],
      "synonyms": [
        {
          "word": "A."
        }
      ],
      "topics": [
        "medicine",
        "sciences"
      ]
    }
  ],
  "word": "a."
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "mul",
        "2": "la",
        "3": "artēria",
        "t": "artery"
      },
      "expansion": "Latin artēria (“artery”)",
      "name": "der"
    },
    {
      "args": {
        "1": "mul",
        "2": "Latin <i class=\"Latn mention\" lang=\"la\">artēria</i> (“artery”)"
      },
      "expansion": "Abbreviation of Latin artēria (“artery”)",
      "name": "abbrev"
    }
  ],
  "etymology_text": "Abbreviation of Latin artēria (“artery”).",
  "forms": [
    {
      "form": "aa.",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "noun",
        "3": "plural",
        "4": "aa."
      },
      "expansion": "a. (plural aa.)",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Translingual abbreviations",
        "Translingual entries with incorrect language header",
        "Translingual lemmas",
        "Translingual nouns",
        "Translingual terms derived from Latin",
        "Translingual terms spelled with .",
        "mul:Medicine"
      ],
      "glosses": [
        "artery"
      ],
      "links": [
        [
          "medicine",
          "medicine"
        ],
        [
          "artery",
          "artery"
        ]
      ],
      "raw_glosses": [
        "(medicine) artery"
      ],
      "topics": [
        "medicine",
        "sciences"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "A."
    }
  ],
  "word": "a."
}