The Collaborative International Dictionary of English v.0.48:
Extirpable \Ex*tir"pa*ble\, a. Capable of being extirpated or eradicated; as, an extirpable plant. --Evelyn. [1913 Webster]WordNet (r) 3.0 (2006):
extirpable adj 1: capable of being totally destroyed or wiped out [syn: exterminable, extirpable]