プログレッシブ和英中辞典(第4版)の解説
くうぜん【空前】
空前の unprecedented；〔記録破りの〕record-breaking
展覧会は空前の盛況だった
The exhibition was an unprecedented [unparalleled] success.
米は空前の豊作だった
We had a record [record-breaking] rice crop.
空前絶後
空前絶後の怪事件だった
It was the strangest case we had ever heard of.