Definitions
1.nounA destructive capacity that exceeds that needed to destroy an enemy; especially with nuclear weapons.
2.noun(by extension) An unnecessary excess of whatever is needed to achieve a goal."24 hours of TV coverage of the US election verged on overkill."
3.nounAn unnecessary excess of disposal because of too high criteria of inspection.
4.verbTo destroy something with more (nuclear) force than is required.
5.verbTo dispose of too many items because of too high criteria of inspection.
6.verbTo do something excessive to achieve a goal.