"1a" meaning in เอสเปรันโต

{
  "lang": "เอสเปรันโต",
  "lang_code": "eo",
  "pos": "adj",
  "pos_title": "คำคุณศัพท์",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages using deprecated templates",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Successfully deprecated templates",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "คำย่อภาษาเอสเปรันโต",
          "parents": [],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "unua"
        }
      ],
      "glosses": [
        "(lang= parameter) คำย่อของ unua"
      ],
      "id": "th-1a-eo-adj-cZuIUj~m",
      "tags": [
        "form-of"
      ]
    }
  ],
  "word": "1a"
}

{
  "lang": "เอสเปรันโต",
  "lang_code": "eo",
  "pos": "adj",
  "pos_title": "คำคุณศัพท์",
  "senses": [
    {
      "categories": [
        "Pages using deprecated templates",
        "Successfully deprecated templates",
        "คำย่อภาษาเอสเปรันโต"
      ],
      "form_of": [
        {
          "word": "unua"
        }
      ],
      "glosses": [
        "(lang= parameter) คำย่อของ unua"
      ],
      "tags": [
        "form-of"
      ]
    }
  ],
  "word": "1a"
}

{
  "called_from": "parser/304",
  "msg": "HTML tag <code> not properly closed",
  "path": [
    "1a"
  ],
  "section": "เอสเปรันโต",
  "subsection": "คำคุณศัพท์",
  "title": "1a",
  "trace": "started on line 1, detected on line 1"
}

{
  "called_from": "parser/1336",
  "msg": "no corresponding start tag found for </code>",
  "path": [
    "1a"
  ],
  "section": "เอสเปรันโต",
  "subsection": "คำคุณศัพท์",
  "title": "1a",
  "trace": ""
}