knockout

American  

[nok-out] / ˈnɒkˌaʊt /

noun

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.

5. a panel in a casing, can, or box, especially 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.

6. Machinery. a device for knocking something loose, as finished work from a lathe chuck.

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adjective

1. that knocks out.

   the knockout punch.

knockout British  

/ ˈnɒkˌaʊt /

noun

1. the act of rendering unconscious

2. a blow that renders an opponent unconscious

3. 1. a competition in which competitors are eliminated progressively

   2. ( as modifier )

      a knockout contest

4. a series of absurd invented games, esp obstacle races, involving physical effort or skill

5. informal a person or thing that is overwhelmingly impressive or attractive

   she's a knockout

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verb

1. to render unconscious, esp by a blow

2. boxing to defeat (an opponent) by a knockout

3. to destroy, damage, or injure badly

4. to eliminate, esp in a knockout competition

5. informal to overwhelm or amaze, esp with admiration or favourable reaction

   I was knocked out by that new song

6. to remove the ashes from (one's pipe) by tapping

Etymology

Origin of knockout

1810–20; 1935–40 knockout for def. 4; noun, adj. use of verb phrase knock out

Explanation

In the sport of boxing, a knockout is a blow that sends one of the boxers to the mat, unable to continue fighting. If you are down and can't rise before the ref counts to ten, consider it a knockout. In full-contact fighting sports, including boxing, karate, and kickboxing, the ultimate goal is a match-winning knockout of the opponent. Not all boxing matches end this way, but a knockout is the most exciting (and dangerous) way for a match to end. This word is also used to mean "gorgeous person," so if someone tells you you're a knockout, you can be sure they mean it as a compliment.

Example Sentences

The Conference League was introduced to give more teams the chance to play proper European football, rather than be eliminated in knockout rounds.

From BBC • May 28, 2026

For the straight knockout format to work, there must be 32 teams in round three.

From BBC • May 28, 2026

Fellow crossover star Francis Ngannou, who pushed Tyson Fury close and suffering a heavy knockout defeat against Anthony Joshua, has set the blueprint for Verhoeven.

From BBC • May 24, 2026

"I think Usyk will be too fluid for the stiff and big Verhoeven. I've got Usyk by knockout in nine."

From BBC • May 23, 2026

“He’s breathing, so that’s good. It’s like he got hit with a knockout juju.”

From "The Manifestor Prophecy" by Angie Thomas

Related Words

• technical knockout