knock·​out | \ ˈnäk-ˌau̇t How to pronounce knockout (audio) \

Definition of knockout

 (Entry 1 of 3)

1a : the act of knocking out : the condition of being knocked out
b(1) : the termination of a boxing match when one boxer has been knocked down and is unable to rise and resume boxing within a specified time
c : a blow that knocks out an opponent
2 : a sensationally striking, appealing, or attractive person or thing



Definition of knockout (Entry 2 of 3)

1 : causing a knockout a knockout blow
2 : sensationally striking, appealing, or attractive a knockout dress
3 : having all or part of a gene eliminated or inactivated by genetic engineering knockout mice predisposed to diabetes mellitus

knock out

knocked out; knocking out; knocks out

Definition of knock out (Entry 3 of 3)

transitive verb

1 : to produce roughly or hastily
2a(1) : to defeat (a boxing opponent) by a knockout
(2) : to make unconscious the drug knocked him out
b : to make inoperative or useless electricity was knocked out by the storm
c : to get rid of : eliminate knocked out illegal gambling
3 : to tire out : exhaust knocked themselves out with work
4 : to cause (an opposing pitcher) to be removed from a baseball game by a batting rally

Examples of knockout in a Sentence

Noun He won the match by a knockout. He scored a knockout in the fourth round. She's a real knockout in that dress. Adjective The Wimbledon tennis tournament is a knockout competition. a knockout sports car that's the talk of the neighborhood Verb the entire staff knocked itself out getting the project finished on time See More
Recent Examples on the Web: Noun To wrap it all up in a final boxing metaphor, the Z is swinging wildly hoping for a lucky knockout, while the Supra confidently lands unanswered precision strikes. Mark Takahashi, Car and Driver, 10 June 2022 Undefeated Upper Arlington flexed their muscles early and often on their way to a convincing 20-2 knockout of the Lady Aves. Scott Springer, The Enquirer, 1 June 2022 López’s knockout showed the blend of power, precision, art, science and violence that has made Cuba’s amateur boxing program the world’s best. New York Times, 30 May 2022 Romero certainly has power (and an 86% knockout percentage to go with it). Josh Katzowitz, Forbes, 28 May 2022 Liverpool’s route through the knockout phase past Inter Milan, Benfica and Villarreal seemed relatively smooth. Rob Harris, ajc, 28 May 2022 Consider that Coinbase bounded into the 500 for the first time this year based on its knockout 2021 performance, as crypto trading boomed. Geoff Colvin, Fortune, 27 May 2022 Being able to have the players come together, play a little knockout, just have fun with each other. Mary Kay Cabot, cleveland, 25 May 2022 Jean Reno is the titular hitman, Natalie Portman, his youthful protégé, and Gary Oldman, the show-stealing villain in Luc Besson’s knockout 1994 action thriller. Los Angeles Times, 19 May 2022 Recent Examples on the Web: Adjective June Michigan consumer sentiment came in worse than expected and even hit a record low, but the knockout punch came on the inflation front. John Dobosz, Forbes, 13 June 2022 Alex Epstein, author of The Moral Case for Fossil Fuels, has delivered another knockout punch against Green ideology. Robert Zubrin, National Review, 4 June 2022 However, the knockout punch came from an unexpected source. Kevin Baxter, Los Angeles Times, 13 May 2022 Don’t miss the Palm Springs Aerial Tramway — the world’s largest rotating tramcar — for a white-knuckle ride with knockout views. Alesandra Dubin, Woman's Day, 19 May 2022 Consequently, FC Cincinnati is likely to go deeper into its pool of senior players in the knockout match against New England. Pat Brennan, The Enquirer, 10 May 2022 The last time it was eliminated in a knockout round after winning the first leg was in the 2001-02 quarterfinals against Bayer Leverkusen. Mark Heim |, al, 3 May 2022 Much of this flows from a truly knockout performance from 18-year-old Maya Lou Hlava in the lead role of Wendla. Chris Jones, Chicago Tribune, 2 May 2022 This is, now, what the knockout stages of the Champions League do. New York Times, 29 Apr. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'knockout.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of knockout


1887, in the meaning defined at sense 1a


1818, in the meaning defined at sense 1


1856, in the meaning defined at sense 1

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Time Traveler for knockout

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The first known use of knockout was in 1818

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Dictionary Entries Near knockout

knock on the door of


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Statistics for knockout

Last Updated

20 Jun 2022

Cite this Entry

“Knockout.” Dictionary, Merriam-Webster, Accessed 28 Jun. 2022.

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More Definitions for knockout


knock·​out | \ ˈnäk-ˌau̇t How to pronounce knockout (audio) \

Medical Definition of knockout

: having all or part of a gene eliminated or inactivated by genetic engineering knockout mice predisposed to diabetes mellitus serve as animal models in the study of human diabetes

More from Merriam-Webster on knockout

Nglish: Translation of knockout for Spanish Speakers

Britannica English: Translation of knockout for Arabic Speakers Encyclopedia article about knockout


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