KO

or K.O., k.o., kay·o

[ noun key-oh, key-oh; verb key-oh ]

/ noun ˈkeɪˈoʊ, ˈkeɪˌoʊ; verb ˈkeɪˈoʊ /

Slang.

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See synonyms for KO on Thesaurus.com

noun, plural KO's.

a knockout in boxing.

verb (used with object), KO'd, KO'ing.

to knock unconscious, especially in a boxing match; knock out.

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Origin of KO

First recorded in 1920–25; initial letters of knock out

How to use KO in a sentence

“Gronkowski” itself never manages to sound more erotic than the name of a hearty Polish stew or a D-list WWE performer.
‘A Gronking to Remember’ Speed Read: 8 Naughtiest Bits|Emily Shire|January 7, 2015|DAILY BEAST
I take calcium and vitamin D supplements, but prescription medications are generally only for women in menopause.
You’re Never ‘Cured’ of an Eating Disorder|Carrie Arnold|December 20, 2014|DAILY BEAST
Then Pascal responds (in all caps) with, “BUT WE DIDNT WIN A D [sic] YOU KNOW HIM.”
Exclusive: Sony Emails Blast David O. Russell For Allegedly ‘Feeling Up’ Transgender Niece|William Boot|December 14, 2014|DAILY BEAST
The move gets an “A” for symbolism and a “D” for everything else.
Sony Blames North Korea for Hacking, but Washington Left Them Completely Vulnerable|Gordon G. Chang|December 3, 2014|DAILY BEAST

Sen. Claire McCaskill (D-MO), a leading voice on police demilitarization, was supportive of the White House announcement.
SWAT Lobby Shoots to Kill Police Reform After Ferguson|Tim Mak|December 2, 2014|DAILY BEAST
C was a Captain, all covered with lace; D was a drunkard, and had a red face.
Boys and Girls Bookshelf; a Practical Plan of Character Building, Volume I (of 17)|Various
D'o l'on peut aussy veoir, quelle esperance il y a de planter une belle chrestient par tels evangelistes.
The Jesuit Relations and Allied Documents, Vol. II: Acadia, 1612-1614|Various
Neither of us spoke again, and at length the squat log buildings of Pend d' Oreille loomed ahead of us in the night.
Raw Gold|Bertrand W. Sinclair
He picked out that simple little study of Cramer in D major in the first book—you know it well—and asked me to play it.
Music-Study in Germany|Amy Fay
(d) Excess balances may, at the convenience of each federal reserve bank, remain deposited with the gold settlement fund.
Readings in Money and Banking|Chester Arthur Phillips

British Dictionary definitions for KO

k.o.

/ (ˈkeɪˈəʊ) /

verb KO's, KO'ing, KO'd, k.o.'s, k.o.'ing or k.o.'d

a slang term for knock outSee knockout

noun plural KO's or k.o.'s

a slang term for knockout

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012