Act of knocking out, or state of being knocked out; the act of rendering a person unconscious by a blow.

a blow which causes a person to become unconscious.

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.

A tournament form, usually in team games where only the winning team from each round advances. The losing team is removed from play. In a double knockout a team is removed from play only after losing two matches.

(1) a form of tournament in which the winners of matches progress to the next round.(2) a three-suit squeeze in which one of the losing options is to part with a trump.

A ruling where the referee stops the bout and declares a boxer the winner if his opponent has been down for the count of 10.

a blow that renders the opponent unconscious

A ruling by the referee stopping a fight and declaring one boxer the winner if his opponent has been down for a count of 10.

A ruling where the referee stops the contest and declares a contestant the winner if his or her opponent cannot continue.

There was no such term in prize ring days, and in any case it is a misnomer. A man unable to come to ‘scratch' or ‘toe the line' was counted out of time.

Knockout (also referred to as a K.O. or knock), is a winning criterion in several full-contact combat sports, such as boxing, kickboxing, Muay Thai, mixed martial arts and others sports involving striking. A knockout is usually awarded when one participant is unable to rise from the canvas within a specified period of time, typically because of fatigue, injury (serious or otherwise incapacitating, e.g. a bleeding cut above the eye can blind a fighter), loss of balance or unconsciousness.