k.o.

K|O «KAY OH», verb, K|O'd, K|O'ing, noun, plural K|O's. Slang.

–v.t.

to knock out.

–n.

a knockout. Also, kayo.

╂[apparently < k(nock) o(ut)]

KO (no periods), K.O., or k.o.,

Boxing. knockout.