"6.ª" meaning in Spanish

{
  "head_templates": [
    {
      "args": {
        "1": "es",
        "2": "adjective",
        "g": "f"
      },
      "expansion": "6.ª f",
      "name": "head"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 2 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "6th (abbreviation of sixth)"
      ],
      "id": "en-6.ª-es-adj-zQgn5pIj",
      "links": [
        [
          "6th",
          "6th"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "word": "6.ª"
}

{
  "head_templates": [
    {
      "args": {
        "1": "es",
        "2": "adjective",
        "g": "f"
      },
      "expansion": "6.ª f",
      "name": "head"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "Pages with 2 entries",
        "Spanish adjectives",
        "Spanish entries with incorrect language header",
        "Spanish lemmas",
        "Spanish terms spelled with .",
        "Spanish terms spelled with numbers",
        "Spanish terms spelled with ª"
      ],
      "glosses": [
        "6th (abbreviation of sixth)"
      ],
      "links": [
        [
          "6th",
          "6th"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "word": "6.ª"
}