die out

Verb

die out (third-person singular simple present dies out, present participle dying out, simple past and past participle died out)

1. (idiomatic) To become extinct.
   • The dinosaurs died out a long time ago.
   • The original family who had begun to build a palace to rival Nonesuch had died out before they had put up little more than the gateway,[…].1963, Margery Allingham, chapter 1, in The China Governess: A Mystery, London: Chatto & Windus, →OCLC

   Synonyms:

   die off

2. (idiomatic) To cease gradually.
   • The prejudice has died out.
   • However, apart from all this, the Chief was a grand old man, belonging to a class of individualists which seems to be dying out in these days, when standard behaviour seems to be as prevalent as standard designs.1945 January and February, A Former Pupil, “Some Memories of Crewe Works—III”, in Railway Magazine, page 14