1

knockout

noun knock·out \ ˈnäk-ˌau̇t \
|Updated on: 21 Jul 2018

Definition of knockout

1 a : 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

Examples of knockout in a Sentence

  1. He won the match by a knockout.

  2. He scored a knockout in the fourth round.

  3. She's a real knockout in that dress.

Recent Examples of knockout from the Web

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

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2

knockout

adjective

Definition of knockout

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

Examples of knockout in a Sentence

  1. The Wimbledon tennis tournament is a knockout competition.

  2. a knockout sports car that's the talk of the neighborhood

First Known Use of knockout

1818

in the meaning defined at sense 1

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knock out

verb

Definition of knock out

1 : to produce roughly or hastily
2 a (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 knock out in a Sentence

  1. the entire staff knocked itself out getting the project finished on time

First Known Use of knock out

1856

in the meaning defined at sense 1

See Words from the same year
NEW! Time Traveler

knock out Synonyms


Medical Dictionary

knockout

adjective knock·out \ ˈnäk-ˌau̇t \

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


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