"空前" meaning in Japanese

{
  "forms": [
    {
      "form": "空前",
      "ruby": [
        [
          "空",
          "くう"
        ],
        [
          "前",
          "ぜん"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "kūzen",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "くうぜん"
      },
      "expansion": "空(くう)前(ぜん) • (kūzen)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Japanese entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese links with redundant wikilinks",
          "parents": [
            "Links with redundant wikilinks",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Japanese terms with redundant sortkeys",
          "parents": [
            "Terms with redundant sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "derived": [
        {
          "roman": "kūzenzetsugo",
          "ruby": [
            [
              "空前絶後",
              "くうぜんぜつご"
            ]
          ],
          "word": "空前絶後"
        }
      ],
      "examples": [
        {
          "english": "a tragedy unprecedented in the history of crime in Japan",
          "roman": "Nihon hanzai shijō kūzen no sangeki",
          "ruby": [
            [
              "日本犯罪史上",
              "にほんはんざいしじょう"
            ],
            [
              "空前",
              "くうぜん"
            ],
            [
              "惨劇",
              "さんげき"
            ]
          ],
          "text": "日本犯罪史上空前の惨劇"
        }
      ],
      "glosses": [
        "being unprecedented"
      ],
      "id": "en-空前-ja-noun-jgcm3yVy",
      "links": [
        [
          "unprecedented",
          "unprecedented"
        ]
      ],
      "synonyms": [
        {
          "roman": "mizou",
          "ruby": [
            [
              "未曽有",
              "みぞう"
            ]
          ],
          "word": "未曽有"
        },
        {
          "roman": "zenrei ga nai",
          "ruby": [
            [
              "前例",
              "ぜんれい"
            ]
          ],
          "word": "前例がない"
        }
      ]
    }
  ],
  "word": "空前"
}

{
  "derived": [
    {
      "roman": "kūzenzetsugo",
      "ruby": [
        [
          "空前絶後",
          "くうぜんぜつご"
        ]
      ],
      "word": "空前絶後"
    }
  ],
  "forms": [
    {
      "form": "空前",
      "ruby": [
        [
          "空",
          "くう"
        ],
        [
          "前",
          "ぜん"
        ]
      ],
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "kūzen",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "くうぜん"
      },
      "expansion": "空(くう)前(ぜん) • (kūzen)",
      "name": "ja-noun"
    }
  ],
  "lang": "Japanese",
  "lang_code": "ja",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Japanese entries with incorrect language header",
        "Japanese lemmas",
        "Japanese links with redundant wikilinks",
        "Japanese nouns",
        "Japanese terms spelled with first grade kanji",
        "Japanese terms spelled with second grade kanji",
        "Japanese terms with redundant sortkeys",
        "Japanese terms with usage examples",
        "Japanese terms written with two Han script characters"
      ],
      "examples": [
        {
          "english": "a tragedy unprecedented in the history of crime in Japan",
          "roman": "Nihon hanzai shijō kūzen no sangeki",
          "ruby": [
            [
              "日本犯罪史上",
              "にほんはんざいしじょう"
            ],
            [
              "空前",
              "くうぜん"
            ],
            [
              "惨劇",
              "さんげき"
            ]
          ],
          "text": "日本犯罪史上空前の惨劇"
        }
      ],
      "glosses": [
        "being unprecedented"
      ],
      "links": [
        [
          "unprecedented",
          "unprecedented"
        ]
      ]
    }
  ],
  "synonyms": [
    {
      "roman": "mizou",
      "ruby": [
        [
          "未曽有",
          "みぞう"
        ]
      ],
      "word": "未曽有"
    },
    {
      "roman": "zenrei ga nai",
      "ruby": [
        [
          "前例",
          "ぜんれい"
        ]
      ],
      "word": "前例がない"
    }
  ],
  "word": "空前"
}