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Synonyms

knockout

American  
[nok-aut] / ˈnɒkˌaʊt /

noun

  • knockouts
    plural
  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.


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

    1. a competition in which competitors are eliminated progressively

    2. ( as modifier )

      a knockout contest

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

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

    she's a knockout

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Noun Inflected Forms


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.

Keep Reading on Vocabulary.com

Vocabulary lists containing knockout

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

They do a knockout version of “Silver Threads and Golden Needles.”

From The Wall Street Journal ● Oct. 22, 2026

Over the past two seasons, Premier League clubs have played 21 knockout ties against European opposition in the Conference League and Europa League - and won all 21.

From BBC ● Oct. 22, 2026

Fans of the game have long celebrated its full-bore regular season, when an October contest can be a de facto knockout.

From The Wall Street Journal ● Oct. 18, 2026

Asked for his prediction, Wardley added: "Revenge, Fabio Wardley, knockout win."

From BBC ● Oct. 16, 2026

All I do is sink to my knees, felled by the words that could deliver such a knockout blow.

From "I Am the Messenger" by Markus Zusak

Since fighting his first professional match in 2020, Vargas Jr. himself has built a steady record in the ring with 15 knockouts in 17 wins.

From Los Angeles Times ● Sep. 12, 2026

Itauma, 21, has been widely tipped as the next star of heavyweight boxing, with 12 knockouts in 14 professional victories.

From BBC ● Aug. 4, 2026

Diomande was one of the outstanding performers in the group stage, helping the Ivorians progress to the World Cup knockouts for the first time.

From BBC ● Jul. 17, 2026

Six of his goals came in the group stage and two in the knockouts.

From BBC ● Jul. 8, 2026

Louis had battled his way through twenty-seven professional matches with twenty-three knockouts and no defeats to reach his current status as the number one challenger in the world.

From "The Boys in the Boat: Nine Americans and Their Epic Quest for Gold at the 1936 Berlin Olympics" by Daniel James Brown

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