"tvær" meaning in Icelandic

{
  "head_templates": [
    {
      "args": {
        "1": "is",
        "2": "numeral form"
      },
      "expansion": "tvær",
      "name": "head"
    }
  ],
  "lang": "Icelandic",
  "lang_code": "is",
  "pos": "num",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Icelandic entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "tveir"
        }
      ],
      "glosses": [
        "feminine nominative/accusative of tveir"
      ],
      "id": "en-tvær-is-num-2bYzhEvu",
      "links": [
        [
          "tveir",
          "tveir#Icelandic"
        ]
      ],
      "tags": [
        "accusative",
        "feminine",
        "form-of",
        "nominative"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[tvaiːr]"
    },
    {
      "rhymes": "-aiːr"
    }
  ],
  "word": "tvær"
}

{
  "head_templates": [
    {
      "args": {
        "1": "is",
        "2": "numeral form"
      },
      "expansion": "tvær",
      "name": "head"
    }
  ],
  "lang": "Icelandic",
  "lang_code": "is",
  "pos": "num",
  "senses": [
    {
      "categories": [
        "Icelandic entries with incorrect language header",
        "Icelandic non-lemma forms",
        "Icelandic numeral forms",
        "Icelandic terms with IPA pronunciation",
        "Rhymes:Icelandic/aiːr",
        "Rhymes:Icelandic/aiːr/1 syllable"
      ],
      "form_of": [
        {
          "word": "tveir"
        }
      ],
      "glosses": [
        "feminine nominative/accusative of tveir"
      ],
      "links": [
        [
          "tveir",
          "tveir#Icelandic"
        ]
      ],
      "tags": [
        "accusative",
        "feminine",
        "form-of",
        "nominative"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[tvaiːr]"
    },
    {
      "rhymes": "-aiːr"
    }
  ],
  "word": "tvær"
}