KO

or K.O., k.o., kay·o

[ noun key-oh, key-oh; verb key-oh ]
/ noun ˈkeɪˈoʊ, ˈkeɪˌoʊ; verb ˈkeɪˈoʊ /
Slang.

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.

QUIZZES

LEARN THE SPANISH WORDS FOR THESE COMMON ANIMALS!

Are you learning Spanish? Or do you just have an interest in foreign languages? Either way, this quiz on Spanish words for animals is for you.
Question 1 of 13
How do you say “cat” 🐈 in Spanish?

Origin of KO

First recorded in 1920–25; initial letters of knock out
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for KO

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