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

Our model gives each of Brazil, Germany, Belgium, Spain, France, Portugal, France, England and world champions Argentina at least a 95 per chance of reaching the knockout phase. —Oliver Kay, New York Times, 11 June 2026

What is the format for the World Cup Round of 32 knockout stage? —Mark Harris, FOXNews.com, 10 June 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

Damaging storms swept through the Midwest, knocking out power to hundreds of thousands of customers and causing more than a thousand flight delays or cancellations at Chicago airports. —Chicago Tribune, 11 June 2026

Strong storms swept through the Pittsburgh area on Thursday afternoon, leaving behind a trail of damage and even temporarily knocking out power at the Pittsburgh International Airport. —Madeline Bartos, CBS News, 11 June 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