Awnser:
Annihilate- Destroy utterly; obliterate
annihilate. Killing ends when the thing you are killing (your sworn enemy, all hope, a pesky mosquito) is dead. Annihilate goes farther-when you annihilate something, you wipe all trace of it from the earth. You kill a person, but you annihilate a tribe, a town, or even a species.
