1. 形容詞
   因遺失而不存在的
   因受毀壞而已不存在的
   

   同義字詞
   bygone,bypast,dead,defunct,departed,done,expired,extinct,gone,vanished
   

例句

1. Liaison between the 141st and 142nd was poor from the start and became nonextant as the day wore on.
2. The theme of a witches' sabbath, the central theme in all subsequent "Night on Bald Mountain" projects, appears to have been derived from the nonextant play "The Witch" (, "Ved'ma", "Witch") by Baron Georgiy Mengden, a military friend of the composer.