Definition of KO in English:

KO

noun

Boxing
informal
  • A knockout in a boxing match.

    See also kayo
    stunning blow, finishing blow
    View synonyms

verb

[WITH OBJECT]Boxing
informal
  • Knock (an opponent) out in a boxing match.

    • ‘Conn had KO'd his last four opponents, including heavyweights Buddy Knox and Gunnar Barlund, both in the 8th rounds.’
    • ‘Those days may have ended when Mike Tyson got KO'd by Buster Douglas.’
    • ‘In his first fight as a pro, Foreman KO'd Don Waldheim in the third round an hour before Frazier and Quarry fought.’
    • ‘It's sort of like when Buster Douglas KO'd Mike Tyson.’
    • ‘His final 5 bouts following the McClellan tragedy ended with a record of 2-3 with Benn being KO'd on 2 of those occasions.’
    knocked out, insensible, senseless, insentient, insensate, passed out, comatose, in a coma, inert
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Origin

1920s: abbreviation.

Pronunciation:

KO

/ˌkāˈō/