"前代未聞" meaning in All languages combined

{
  "categories": [
    {
      "kind": "other",
      "name": "テンプレート:pronに引数が用いられているページ",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "日本語",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "日本語 名詞",
      "parents": [],
      "source": "w"
    }
  ],
  "forms": [
    {
      "form": "ぜんだいみもん"
    },
    {
      "form": "せんだいみもん"
    }
  ],
  "lang": "日本語",
  "lang_code": "ja",
  "pos": "noun",
  "pos_title": "名詞",
  "senses": [
    {
      "glosses": [
        "今までに聞いたこともないような珍しいこと。"
      ],
      "id": "ja-前代未聞-ja-noun-WqVkOM7U"
    }
  ],
  "synonyms": [
    {
      "word": "破天荒"
    },
    {
      "word": "空前絶後"
    }
  ],
  "word": "前代未聞"
}

{
  "categories": [
    {
      "kind": "other",
      "name": "朝鮮語",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "朝鮮語_名詞",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "朝鮮語",
  "lang_code": "ko",
  "pos": "noun",
  "pos_title": "名詞",
  "senses": [
    {
      "glosses": [
        "（日本語に同じ）前代未聞。"
      ],
      "id": "ja-前代未聞-ko-noun-JzPQDZ8u"
    }
  ],
  "word": "前代未聞"
}

{
  "categories": [
    "テンプレート:pronに引数が用いられているページ",
    "日本語",
    "日本語 名詞"
  ],
  "forms": [
    {
      "form": "ぜんだいみもん"
    },
    {
      "form": "せんだいみもん"
    }
  ],
  "lang": "日本語",
  "lang_code": "ja",
  "pos": "noun",
  "pos_title": "名詞",
  "senses": [
    {
      "glosses": [
        "今までに聞いたこともないような珍しいこと。"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "破天荒"
    },
    {
      "word": "空前絶後"
    }
  ],
  "word": "前代未聞"
}

{
  "categories": [
    "朝鮮語",
    "朝鮮語_名詞"
  ],
  "lang": "朝鮮語",
  "lang_code": "ko",
  "pos": "noun",
  "pos_title": "名詞",
  "senses": [
    {
      "glosses": [
        "（日本語に同じ）前代未聞。"
      ]
    }
  ],
  "word": "前代未聞"
}