1. no longer in existence; lost or especially having died out leaving no living representatives

- an extinct species of fish

- an extinct royal family

- extinct laws and customs

Similar word(s): nonexistent, dead, nonextant

2. (of e.g. volcanos) permanently inactive

- an extinct volcano

Similar word(s): dead

3. being out or having grown cold

- threw his extinct cigarette into the stream

Similar word(s): dead, out

Sentences with extinct as an adjective:

- Poor Edward's cigarillo was already extinct.

- The dinosaurs have been extinct for millions of years.

- Most of the volcanos on this island are now extinct.