I. ˌō-vər-ˈkil transitive verb
Date: 1957
: to obliterate (a target) with more nuclear force than required
II. ˈō-vər-ˌkil noun
Date: 1958
1. : a destructive capacity greatly exceeding that required for a given target
2. : an excess of something (as a quantity or an action) beyond what is required or suitable for a particular purpose
publicity overkill
an overkill in weaponry
3. : killing in excess of what is intended or required