Synonyms for Decimate:

n.

•decimate (noun)
carry off, annihilate, extinguish, eradicate, eliminate, wipe out.

v.

•destroy (verb)
desolate, bulldoze, mow down, wreck, rip to shreds, lay waste, destroy, wipe out, raze, vaporize, disintegrate, abolish, butcher, slaughter, level, tear down, atomize, flatten, eradicate, smash, demolish, dismantle, extirpate, devastate, massacre, pulverize, exterminate, annihilate.

Other synonyms:

•defeat
mow down.
•destroy
pulverize.
•kill
exterminate, slaughter.
•ruin
lay waste.
•take apart
dismantle.