adj. 1. (Psychol.) caused to die out because of the absence or withdrawal of reinforcement; -- of a conditioned response. [ WordNet 1.5 ]
2. no longer burning; -- of a fire. Syn. -- extinct, out(predicate), quenched. [ WordNet 1.5 ]
3. no longer existing; -- of species. Syn. -- dead. [ WordNet 1.5 ]