KO

1 of 2

noun

(ˌ)kā-ˈō  ˈkā-(ˌ)ō 

: knockout entry 1

KO

2 of 2

verb

KO'd kā-ˈōd 

ˈkā-(ˌ)ōd

; KO'ing kā-ˈō-iŋ 

ˈkā-(ˌ)ō-iŋ

transitive verb

: to knock out (as in boxing)

Examples of KO in a Sentence

Noun

He scored a KO in the second round.

Verb

He was KO'd in the second round.

Recent Examples on the Web

Noun

Itauma turned pro three years ago in a debut KO victory that lasted just 23 seconds. — ABC News, 28 Mar. 2026

The challenge of doing so, however, was twofold, says Karl Fournier, co-founder of Studio KO. — Lindsey Tramuta, Travel + Leisure, 23 May 2026

Yakhyaev's 8-second KO stands out, too, and could likely lead to Julius Walker's release from the promotion. — Brian Mazique, Forbes.com, 27 June 2026

It’s commonly known as a walkoff KO, and O’Malley has mastered the celebration in recent years. — Mark Puleo, New York Times, 15 June 2026

Word History

Etymology

Noun

knock out

First Known Use

Noun

1911, in the meaning defined above

Verb

1926, in the meaning defined above

Rhymes for KO

• beau
• beaut
• beaux
• blow
• bro
• coe
• crow
• doe
• doh
• dough
• eau
• eaux

Kids Definition

KO

1 of 2 noun

(ˈ)kā-ˈō 

ˈkā-ō

plural KO's

: a knockout in boxing

KO

2 of 2 verb

KO'd kā-ˈōd 

ˈkā-ōd

; KO'ing -ˈō-iŋ 

-ō-

: to knock out in boxing