"serbsku" meaning in Polish

{
  "head_templates": [
    {
      "args": {
        "1": "pl",
        "2": "adjective form"
      },
      "expansion": "serbsku",
      "name": "head"
    }
  ],
  "hyphenation": [
    "ser‧bsku"
  ],
  "lang": "Polish",
  "lang_code": "pl",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Polish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "old masculine dative singular of serbski"
      ],
      "id": "en-serbsku-pl-adj-x-A0VILo",
      "links": [
        [
          "serbski",
          "serbski#Polish"
        ]
      ],
      "synonyms": [
        {
          "word": "serbskiemu"
        }
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈsɛr.psku/"
    },
    {
      "rhymes": "-ɛrpsku"
    }
  ],
  "word": "serbsku"
}

{
  "head_templates": [
    {
      "args": {
        "1": "pl",
        "2": "adjective form"
      },
      "expansion": "serbsku",
      "name": "head"
    }
  ],
  "hyphenation": [
    "ser‧bsku"
  ],
  "lang": "Polish",
  "lang_code": "pl",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "Polish 2-syllable words",
        "Polish adjective forms",
        "Polish entries with incorrect language header",
        "Polish non-lemma forms",
        "Polish terms with IPA pronunciation",
        "Rhymes:Polish/ɛrpsku",
        "Rhymes:Polish/ɛrpsku/2 syllables"
      ],
      "glosses": [
        "old masculine dative singular of serbski"
      ],
      "links": [
        [
          "serbski",
          "serbski#Polish"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈsɛr.psku/"
    },
    {
      "rhymes": "-ɛrpsku"
    }
  ],
  "synonyms": [
    {
      "word": "serbskiemu"
    }
  ],
  "word": "serbsku"
}