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

The top four advance directly to the quarterfinals and the clubs finishing between fifth and 12th compete in knockout phase playoffs in February. — ABC News, 21 Sep. 2026

The new track fuses Scott’s trap foundation with Homem-Christo’s cinematic electronic soundscape, making for what’s sure to be a knockout background song for the beloved game. — Kyle Denis, Billboard, 18 Sep. 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

Water from the storm surge and heavy rain filled streets and surrounded homes as near-hurricane-force winds knocked out power. — Brian Tang, The Conversation, 30 Sep. 2026

In East of Eden, Pugh delivers yet another knock out performance as Cathy Ames, the distant mother and madam at the center of Steinbeck’s multigenerational family saga and biblical allegory. — Chris Murphy, Vanity Fair, 30 Sep. 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