"dat" meaning in Czech

{
  "head_templates": [
    {
      "args": {
        "1": "cs",
        "2": "proper noun form"
      },
      "expansion": "dat",
      "name": "head"
    }
  ],
  "lang": "Czech",
  "lang_code": "cs",
  "pos": "name",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Czech entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "data"
        }
      ],
      "glosses": [
        "genitive plural of data"
      ],
      "id": "en-dat-cs-name-H75oF8~V",
      "links": [
        [
          "data",
          "data#Czech"
        ]
      ],
      "tags": [
        "form-of",
        "genitive",
        "plural"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈdat]"
    }
  ],
  "word": "dat"
}

{
  "categories": [
    "West Frisian conjunctions",
    "West Frisian determiner forms",
    "West Frisian entries with incorrect language header",
    "West Frisian lemmas",
    "West Frisian non-lemma forms",
    "West Frisian pronouns",
    "West Frisian terms with IPA pronunciation"
  ],
  "head_templates": [
    {
      "args": {
        "1": "cs",
        "2": "proper noun form"
      },
      "expansion": "dat",
      "name": "head"
    }
  ],
  "lang": "Czech",
  "lang_code": "cs",
  "pos": "name",
  "senses": [
    {
      "categories": [
        "Czech entries with incorrect language header",
        "Czech non-lemma forms",
        "Czech proper noun forms",
        "Czech terms with IPA pronunciation"
      ],
      "form_of": [
        {
          "word": "data"
        }
      ],
      "glosses": [
        "genitive plural of data"
      ],
      "links": [
        [
          "data",
          "data#Czech"
        ]
      ],
      "tags": [
        "form-of",
        "genitive",
        "plural"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈdat]"
    }
  ],
  "word": "dat"
}