"a-" meaning in Translingual

{
  "etymology_templates": [
    {
      "args": {
        "1": "mul",
        "2": "grc",
        "3": "ἀ-",
        "t": "not, without"
      },
      "expansion": "Ancient Greek ἀ- (a-, “not, without”)",
      "name": "der"
    }
  ],
  "etymology_text": "From the Ancient Greek ἀ- (a-, “not, without”).",
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "prefix"
      },
      "expansion": "a-",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages using catfix",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 52 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Translingual entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Used to form taxonomic names indicating a lack of some feature that might be expected"
      ],
      "id": "en-a--mul-prefix-awFODyjB",
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "a-"
}

{
  "categories": [
    "Pages with 52 entries",
    "Pages with entries"
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "mul",
        "2": "grc",
        "3": "ἀ-",
        "t": "not, without"
      },
      "expansion": "Ancient Greek ἀ- (a-, “not, without”)",
      "name": "der"
    }
  ],
  "etymology_text": "From the Ancient Greek ἀ- (a-, “not, without”).",
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "prefix"
      },
      "expansion": "a-",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        "Pages using catfix",
        "Pages with 52 entries",
        "Pages with entries",
        "Translingual entries with incorrect language header",
        "Translingual lemmas",
        "Translingual prefixes",
        "Translingual terms derived from Ancient Greek"
      ],
      "glosses": [
        "Used to form taxonomic names indicating a lack of some feature that might be expected"
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "a-"
}