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
This week, just steps from the garden, Musée Yves Saint Laurent Marrakech (mYSLm), a 43,000-square-foot museum designed by the architectural firm Studio KO, opens its doors to the public. — Condé Nast, Condé Nast Traveler, 30 Aug. 2026 Kennedy Nzechukwu Heavyweight KO in Round 1 Chris Padilla def. — Brian Mazique, Forbes.com, 23 Aug. 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 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 4 Sep. 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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