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

Appeared in the March 26, 2026, print edition as 'Another Supreme Court Knockout'.

From The Wall Street Journal • Mar. 25, 2026

They have also not exited a global event without winning a match since the International Cricket Council Knockout event in 2000.

From BBC • Feb. 28, 2025

Knockout experiments in lab-grown human muscle cells by the team confirmed the importance of these nuclei in maintaining muscle function5.

From Science Daily • Apr. 15, 2024

They added a high school basketball Knockout Competition that features all of the state’s 92 counties and added three new legacy projects, increasing the number from 21 to 24.

From Seattle Times • Feb. 14, 2024

Kendrick became a Knockout King, and that’s who he is today.

From "They Both Die at the End" by Adam Silvera

Related Words

• technical knockout