annihilative

from WordNet (r) 3.0 (2006)

annihilative
    adj 1: wreaking or capable of wreaking complete destruction;
           "possessing annihilative power"; "a devastating
           hurricane"; "the guns opened a withering fire" [syn:
           {annihilative}, {annihilating}, {devastating},
           {withering}]

from The Collaborative International Dictionary of English v.0.48

Annihilative \An*ni"hi*la*tive\, a.
   Serving to annihilate; destructive.
   [1913 Webster]