knockout

1 of 3

noun

knock·​out ˈnäk-ˌau̇t 

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

(2)

: technical knockout

c

: a blow that knocks out an opponent

2

: a sensationally striking, appealing, or attractive person or thing

knockout

2 of 3

adjective

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

3 of 3

verb

knocked out; knocking out; knocks out

transitive verb

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

Synonyms of knockout

Noun

• daze
• trance
• faint
• blackout
• swim

Adjective

• beautiful
• lovely
• gorgeous
• cute
• handsome
• attractive
• pretty
• stunning
• good
• charming

Verb

• wear
• kill
• exhaust
• tire
• drain
• wear out
• burn out

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

Recent Examples on the Web

Noun

With a win on Saturday, Inter Miami advances to the knockout stage of the tournament. — Michelle Kaufman august 7, Miami Herald, 7 Aug. 2026

Malawi lost its final group match to Zambia 2-1 on Wednesday, but secured the group win with six points and a head-to-head tiebreaker over Nigeria, who also qualified for the knockouts. — Pj Green, Kansas City Star, 6 Aug. 2026

Adjective

This is knockout material that reminds you of the lack of courage of most of the Broadway satires that have followed. — Chris Jones, Chicago Tribune, 21 May 2026

The next day all anyone could talk about on that show was the knockout and sultry performance from this unknown new star. — Pete Hammond, Deadline, 30 Apr. 2026

Verb

There will also be a new WAFCON champion this year after Cameroon knocked out 10-time champions Nigeria with a first-half free-kick goal from 19-year-old defender Maeva Nyadjou. — Emily Olsen, New York Times, 11 Aug. 2026

The storms knocked down trees and power lines, knocked out power in some areas and left residents cleaning up their yards. — Adam Thompson, CBS News, 11 Aug. 2026

Word History

First Known Use

Noun

1887, in the meaning defined at sense 1a

Adjective

1818, in the meaning defined at sense 1

Verb

1856, in the meaning defined at sense 1

Phrases Containing knockout

• knockout drops
• technical knockout

Rhymes for knockout

• about
• bailout
• blackout
• blowout
• breakout
• burnout
• buyout
• checkout
• closeout
• cutout
• devout
• dropout

Kids Definition

knockout

1 of 2 noun

knock·​out ˈnäk-ˌau̇t 

1

: the act of knocking out : the condition of being knocked out

2

: something or someone very striking or attractive

knockout adjective

knock out

2 of 2 verb

ˈnäk-ˈau̇t, 

näk-ˈau̇t

: to make unconscious

Medical Definition

knockout

adjective

knock·​out ˈnäk-ˌau̇t 

: 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