overkill

noun

1. the capacity of a nation to destroy, by nuclear weapons, more of an enemy than would be necessary for a military victory.
2. an instance of such destruction.
3. an excess of what is required or suitable, as because of zeal or misjudgment.

noun

1. the capability to deploy more weapons, esp nuclear weapons, than is necessary to ensure military advantage
2. any capacity or treatment that is greater than that required or appropriate

n.1958, from over- + kill (v.). Originally in reference to nuclear arsenals; the general sense is from 1965. The verb is attested from 1946.