KO

1 of 2

noun

(ˌ)kā-ˈō How to pronounce KO (audio) ˈkā-(ˌ)ō How to pronounce KO (audio)
Synonyms of KOnext
: knockout entry 1

KO

2 of 2

verb

KO'd kā-ˈōd How to pronounce KO (audio)
ˈkā-(ˌ)ōd
 ; KO'ing kā-ˈō-iŋ How to pronounce KO (audio)
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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
The challenge of doing so, however, was twofold, says Karl Fournier, co-founder of Studio KO. — Lindsey Tramuta, Travel + Leisure, 23 May 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 Rabid Fans Katie Feeney – Snapchat The Trauma Behind the KO. — Todd Spangler, Variety, 31 Mar. 2026 Rodrigues, entering with a 3-0 run since a February 2025 TKO loss, boasts two knockouts and a decision victory, including a March 2026 first-round KO. — Trent Reinsmith, Forbes.com, 7 July 2026 See All Example Sentences for KO

Word History

Etymology

Noun

knock out

First Known Use

Noun

1911, in the meaning defined above

Verb

1926, in the meaning defined above

Time Traveler
The first known use of KO was in 1911

Rhymes for KO

See All Rhymes for KO

Browse Nearby Words

knysna boxwood
KO
koa
See all Nearby Words

Cite this Entry

“KO.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/KO. Accessed 10 Jul. 2026.

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Kids Definition

KO

1 of 2 noun
(ˈ)kā-ˈō How to pronounce KO (audio)
ˈkā-ō
plural KO's
: a knockout in boxing

KO

2 of 2 verb
KO'd kā-ˈōd How to pronounce KO (audio)
ˈkā-ōd
 ; KO'ing -ˈō-iŋ How to pronounce KO (audio)
-ō-
: to knock out in boxing

More from Merriam-Webster on KO

Britannica.com: Encyclopedia article about KO

Last Updated: - Updated example sentences
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