"серологу" meaning in Ukrainien

{
  "categories": [
    {
      "kind": "other",
      "name": "Formes de noms communs en ukrainien",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Ukrainien",
      "orig": "ukrainien",
      "parents": [],
      "source": "w"
    }
  ],
  "forms": [
    {
      "form": "серо́логу",
      "tags": [
        "canonical"
      ]
    }
  ],
  "lang": "Ukrainien",
  "lang_code": "uk",
  "pos": "noun",
  "pos_title": "Forme de nom commun",
  "raw_tags": [
    "⁽ˢᵉʳᵒˡᵒʰᵘ⁾"
  ],
  "senses": [
    {
      "form_of": [
        {
          "word": "серо́лог"
        }
      ],
      "glosses": [
        "Datif singulier de серо́лог."
      ],
      "id": "fr-серологу-uk-noun-jwSxSiiT"
    },
    {
      "form_of": [
        {
          "word": "серо́лог"
        }
      ],
      "glosses": [
        "Locatif singulier de серо́лог."
      ],
      "id": "fr-серологу-uk-noun-GIjuk2ZF"
    },
    {
      "form_of": [
        {
          "word": "серо́лог"
        }
      ],
      "glosses": [
        "Vocatif singulier de серо́лог."
      ],
      "id": "fr-серологу-uk-noun-8xiWv~LD"
    }
  ],
  "tags": [
    "animate",
    "form-of",
    "masculine"
  ],
  "word": "серологу"
}

{
  "categories": [
    "Formes de noms communs en ukrainien",
    "ukrainien"
  ],
  "forms": [
    {
      "form": "серо́логу",
      "tags": [
        "canonical"
      ]
    }
  ],
  "lang": "Ukrainien",
  "lang_code": "uk",
  "pos": "noun",
  "pos_title": "Forme de nom commun",
  "raw_tags": [
    "⁽ˢᵉʳᵒˡᵒʰᵘ⁾"
  ],
  "senses": [
    {
      "form_of": [
        {
          "word": "серо́лог"
        }
      ],
      "glosses": [
        "Datif singulier de серо́лог."
      ]
    },
    {
      "form_of": [
        {
          "word": "серо́лог"
        }
      ],
      "glosses": [
        "Locatif singulier de серо́лог."
      ]
    },
    {
      "form_of": [
        {
          "word": "серо́лог"
        }
      ],
      "glosses": [
        "Vocatif singulier de серо́лог."
      ]
    }
  ],
  "tags": [
    "animate",
    "form-of",
    "masculine"
  ],
  "word": "серологу"
}