"鵶頭白し" meaning in 日本語

{
  "categories": [
    {
      "kind": "other",
      "name": "日本語",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "日本語 成句",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "カラスの頭が白いはずがないことから。"
  ],
  "forms": [
    {
      "form": "あとうしろし"
    }
  ],
  "lang": "日本語",
  "lang_code": "ja",
  "pos": "phrase",
  "pos_title": "成句",
  "senses": [
    {
      "glosses": [
        "前例がないこと。物事が成功しがたいこと。"
      ],
      "id": "ja-鵶頭白し-ja-phrase-8cdNWcNQ"
    }
  ],
  "synonyms": [
    {
      "word": "亀毛兎角"
    },
    {
      "word": "晦日（みそか）に月が出る"
    }
  ],
  "tags": [
    "idiomatic"
  ],
  "word": "鵶頭白し"
}

{
  "categories": [
    "日本語",
    "日本語 成句"
  ],
  "etymology_texts": [
    "カラスの頭が白いはずがないことから。"
  ],
  "forms": [
    {
      "form": "あとうしろし"
    }
  ],
  "lang": "日本語",
  "lang_code": "ja",
  "pos": "phrase",
  "pos_title": "成句",
  "senses": [
    {
      "glosses": [
        "前例がないこと。物事が成功しがたいこと。"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "亀毛兎角"
    },
    {
      "word": "晦日（みそか）に月が出る"
    }
  ],
  "tags": [
    "idiomatic"
  ],
  "word": "鵶頭白し"
}