Also found in: Dictionary, Thesaurus, Medical, Encyclopedia, Wikipedia.
1. slang A phonetic spelling of "KO," an initialism for "knockout," a victory in boxing in which one's opponent is knocked to the mat and unable to rise within a specific amount of time. He's strong, but he lacks stamina. He'll try to win with a kayo in the early rounds, but if you can avoid his punches, you'll be able to tire him out. She's got more kayos than any other boxer in history.
2. verb, slang To achieve a victory by knockout. He kayoed his opponent in just 45 seconds. Don't worry about kayoing him—focus on your jabs, blocks, and footwork.
3. verb, slang To render someone unconscious. Be careful drinking that stuff. It'll kayo you! Sorry for not calling you back. I sat down after getting home from that hike and was instantly kayoed. He kayoed Jeff with a single punch to the head.
slang Rendered asleep or unconscious, as from drugs, alcohol, fatigue, or a physical blow. Jim started drinking shots whiskey with his beers and was kayoed by 11 PM. Sorry for not calling you back. I sat down after we got home from the hike and was instantly kayoed. Just one punch to Jim's head left him kayoed on the sidewalk.
See also: kayo