KO2 Syllabification: (KO)Pronunciation: /ˌkāˈō/ Boxing, informalDefinition of KO noun a knockout in a boxing match. See also kayo. verb (KO's, KO'ing, KO'd) [with object] knock (an opponent) out in a boxing match. Origin: 1920s: abbreviationKO in other Oxford dictionaries Definition of KO in the British & World English dictionary
