"20." meaning in Icelandic

{
  "head_templates": [
    {
      "args": {
        "1": "is",
        "2": "adjective"
      },
      "expansion": "20.",
      "name": "head"
    }
  ],
  "lang": "Icelandic",
  "lang_code": "is",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Icelandic entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "name": "Icelandic ordinal numbers",
          "parents": [
            "Ordinal numbers",
            "Numbers",
            "All topics",
            "Terms by semantic function",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 4 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "20th"
      ],
      "id": "en-20.-is-adj-e~e7KsZB",
      "links": [
        [
          "20th",
          "20th"
        ]
      ],
      "synonyms": [
        {
          "tags": [
            "masculine"
          ],
          "word": "tuttugasti"
        },
        {
          "tags": [
            "feminine",
            "neuter"
          ],
          "word": "tuttugasta"
        }
      ]
    }
  ],
  "word": "20."
}

{
  "head_templates": [
    {
      "args": {
        "1": "is",
        "2": "adjective"
      },
      "expansion": "20.",
      "name": "head"
    }
  ],
  "lang": "Icelandic",
  "lang_code": "is",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "Icelandic adjectives",
        "Icelandic entries with incorrect language header",
        "Icelandic lemmas",
        "Icelandic ordinal numbers",
        "Icelandic terms spelled with .",
        "Icelandic terms spelled with numbers",
        "Pages with 4 entries",
        "Pages with entries"
      ],
      "glosses": [
        "20th"
      ],
      "links": [
        [
          "20th",
          "20th"
        ]
      ]
    }
  ],
  "synonyms": [
    {
      "tags": [
        "masculine"
      ],
      "word": "tuttugasti"
    },
    {
      "tags": [
        "feminine",
        "neuter"
      ],
      "word": "tuttugasta"
    }
  ],
  "word": "20."
}

{
  "called_from": "linkages/371",
  "msg": "unrecognized linkage prefix: (20th): tuttugasti m, tuttugasta f or n desc=20th rest=tuttugasti m, tuttugasta f or n cls=romanization cls2=romanization e1=True e2=False",
  "path": [
    "20."
  ],
  "section": "Icelandic",
  "subsection": "adjective",
  "title": "20.",
  "trace": ""
}