"čt" meaning in Czech

{
  "head_templates": [
    {
      "args": {
        "1": "cs",
        "2": "noun"
      },
      "expansion": "čt",
      "name": "head"
    }
  ],
  "lang": "Czech",
  "lang_code": "cs",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "Thursday",
          "word": "čtvrtek"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Czech entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Abbreviation of čtvrtek (“Thursday”)."
      ],
      "id": "en-čt-cs-noun-Lw7t5swK",
      "links": [
        [
          "čtvrtek",
          "čtvrtek#Czech"
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈt͡ʃtvr̩tɛk]"
    }
  ],
  "word": "čt"
}

{
  "head_templates": [
    {
      "args": {
        "1": "cs",
        "2": "noun"
      },
      "expansion": "čt",
      "name": "head"
    }
  ],
  "lang": "Czech",
  "lang_code": "cs",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "Thursday",
          "word": "čtvrtek"
        }
      ],
      "categories": [
        "Czech abbreviations",
        "Czech entries with incorrect language header",
        "Czech lemmas",
        "Czech nouns",
        "Czech terms with IPA pronunciation"
      ],
      "glosses": [
        "Abbreviation of čtvrtek (“Thursday”)."
      ],
      "links": [
        [
          "čtvrtek",
          "čtvrtek#Czech"
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈt͡ʃtvr̩tɛk]"
    }
  ],
  "word": "čt"
}