[ key-oh, key-oh; verb key-oh ]
/ ˈkeɪˈoʊ, ˈkeɪˌoʊ; verb ˈkeɪˈoʊ /

noun, plural kay·os, verb, kay·oed, kay·o·ing.

Nearby words

  1. kayes,
  2. kayibanda,
  3. kayibanda, grégoire,
  4. kayla,
  5. kaylied,
  6. kayser-fleischer ring,
  7. kayser-fleischer rings,
  8. kayseri,
  9. kaz daği,
  10. kazachok

Origin of kayo

An Americanism dating back to 1920–25


or K.O., k.o., kay·o

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

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.

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. 2019

British Dictionary definitions for kayos




noun plural kayos

boxing another term for knockout

verb kayoes, kayos, kayoing or kayoed

boxing another term for knock outSee knockout (verb)

Word Origin for kayo

C20: from the initial letters of knock out



/ (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

Word Origin and History for kayos


spelled-out form of K.O. (knockout), from 1923. Also used in 1920s as a slang reversal of OK.

Online Etymology Dictionary, © 2010 Douglas Harper