- the capacity of a nation to destroy, by nuclear weapons, more of an enemy than would be necessary for a military victory.
- an instance of such destruction.
- an excess of what is required or suitable, as because of zeal or misjudgment.
- the capability to deploy more weapons, esp nuclear weapons, than is necessary to ensure military advantage
- 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.