KO
From Longman Dictionary of Contemporary EnglishKOKO1 /ˌkeɪ ˈəʊ $ -ˈoʊ/ the abbreviation of knockoutExamples from the CorpusKO• Dusseldorf remains the capital of mindless extravagance; ostentation rules the KO.• The opponents wanted to deliver a KO, but it backfired on them.KOKO2 verb (past tense and past participle KO’d, present participle KO'ing) [transitive] informal to hit someone so hard that they become unconscious→ See Verb tableExamples from the CorpusKO• Joe Louis KO'd Billy Conn in the eighth round.