D defs.my
Entry 4 senses Webster, 1913

knockout

/näk'-outˌ/ · knock·out · IPA /ˈnɑk.oʊt/
01 n. Act of knocking out, or state of being knocked out; the act of rendering a person unconscious by a blow.
  1. 1.
    Act of knocking out, or state of being knocked out; the act of rendering a person unconscious by a blow.
  2. 2.
    a blow which causes a person to become unconscious.
  3. 3.
    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.(Boxing)
  4. 4.
    a strikingly beautiful woman.[Informal]
Syn. knockout blow, knockout punch.