"najczyściej" meaning in Polish

{
  "head_templates": [
    {
      "args": {
        "1": "pl",
        "2": "superlative adverb"
      },
      "expansion": "najczyściej",
      "name": "head"
    }
  ],
  "hyphenation": [
    "naj‧czyś‧ciej"
  ],
  "lang": "Polish",
  "lang_code": "pl",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Polish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "czysto"
        }
      ],
      "glosses": [
        "superlative degree of czysto"
      ],
      "id": "en-najczyściej-pl-adv-Dem4JwnO",
      "links": [
        [
          "czysto",
          "czysto#Polish"
        ]
      ],
      "tags": [
        "form-of",
        "superlative"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/najˈt͡ʂɨɕ.t͡ɕɛj/"
    },
    {
      "rhymes": "-ɨɕt͡ɕɛj"
    }
  ],
  "word": "najczyściej"
}

{
  "head_templates": [
    {
      "args": {
        "1": "pl",
        "2": "superlative adverb"
      },
      "expansion": "najczyściej",
      "name": "head"
    }
  ],
  "hyphenation": [
    "naj‧czyś‧ciej"
  ],
  "lang": "Polish",
  "lang_code": "pl",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        "Polish 3-syllable words",
        "Polish entries with incorrect language header",
        "Polish non-lemma forms",
        "Polish superlative adverbs",
        "Polish terms with IPA pronunciation",
        "Polish terms with audio links",
        "Rhymes:Polish/ɨɕt͡ɕɛj",
        "Rhymes:Polish/ɨɕt͡ɕɛj/3 syllables"
      ],
      "form_of": [
        {
          "word": "czysto"
        }
      ],
      "glosses": [
        "superlative degree of czysto"
      ],
      "links": [
        [
          "czysto",
          "czysto#Polish"
        ]
      ],
      "tags": [
        "form-of",
        "superlative"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/najˈt͡ʂɨɕ.t͡ɕɛj/"
    },
    {
      "rhymes": "-ɨɕt͡ɕɛj"
    }
  ],
  "word": "najczyściej"
}