The Collaborative International Dictionary of English v.0.48:
Extinguishable \Ex*tin"guish*a*ble\, a. Capable of being quenched, destroyed, or suppressed. [1913 Webster]WordNet (r) 3.0 (2006):
extinguishable adj 1: capable of being extinguished or killed; "an extinguishable fire"; "hope too is extinguishable" [ant: inextinguishable]