A knockout (abbreviated to KO or K.O.) is a fight-ending, winning criterion in several full-contact combat sports, such as boxing, kickboxing, Muay Thai, mixed martial arts, karate, some forms of taekwondo …

The meaning of KNOCKOUT is the act of knocking out : the condition of being knocked out. How to use knockout in a sentence.

If you describe someone or something as a knockout, you think that they are extremely attractive or impressive.

KNOCKOUT definition: an act or instance of knocking out. See examples of knockout used in a sentence.

knock•out (ˈnɒkˌaʊt) n. 1. an act or instance of knocking out. 2. the state or fact of being knocked out. 3. a knockout blow. 4. Informal. a person or thing overwhelmingly attractive, appealing, or successful.

knockout noun [C] (COMPETITION) (US elimination tournament) a competition in which only the winners of each stage play in the next stage, until one competitor or team is the final winner:

a panel in a casing, can, or box, esp. of metal or plastic, so designed that it can readily be removed, as by punching, hammering, or cutting, to provide an opening into the interior: a knockout in a junction box.

In boxing, a knockout is a situation in which a boxer wins the fight by making his or her opponent fall to the ground and be unable to stand up before the referee has counted to ten.

The 2025 NBA Cup knockout rounds have been determined. Here's what to know before those games commence.

• He may not have a knockout punch, but he does have good moves all the way to the bell. • It was a knockout punch of which Indurain, Hinault or Merckx would have been proud.