1. No longer in existence; lost or especially having died out leaving no living representatives
   "an extinct species of fish"; "extinct laws and customs";
   - nonextant
    
2. (of e.g. volcanoes) permanently inactive
   "an extinct volcano"
    
3. Not lit, or having grown cold
   "threw his extinct cigarette into the stream";
   - out

See also: dead, extinction, inexistent [rare], nonexistent

Antonym: active, extant

Encyclopedia: Extinct