knockout
knockout , noun
Act of knocking out, or state of being knocked out; the act of rendering a person unconscious by a blow.
2.
a blow which causes a person to become unconscious.
3.
(Boxing) the winning of a boxing contest by rendering the opponent unable to stand for a specified period, usually a count of ten; -- in contrast to a win by a decision; as, Muhammed Ali won by a knockout in the first round.
4.
a strikingly beautiful woman. [Informal]
Also: knock-out