KO

American  

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

Or K.O.,

noun

plural

KO's

1. a knockout in boxing.

---

verb (used with object)

KO'd, KO'ing

1. to knock unconscious, especially in a boxing match; knock out.

KO British  

/ ˈkeɪˈəʊ /

verb

1. a slang term for knock out See knockout

---

noun

1. a slang term for knockout

Etymology

Origin of KO

First recorded in 1920–25; initial letters of knock out

Example Sentences

During the past several years, Brush has suggested KO, UTZ and HSY in his stock newsletter, Brush Up on Stocks.

From MarketWatch • Feb. 7, 2026

Beverage giant Coca-Cola KO -0.43%decrease; red down pointing triangle , with its global footprint and growing focus on zero-sugar drinks and energy beverages, also fits the mold of a steady performer.

From The Wall Street Journal • Dec. 21, 2025

"We got Justin the good look and KO got the rebound and put it back."

From Barron's • Nov. 12, 2025

They said they would nominate KO leader and former European Council chief Donald Tusk as candidate for prime minister.

From BBC • Nov. 10, 2023

And you never want Daddy to go for the KO.

From "The Hate U Give" by Angie Thomas

Related Words

• beating
• blow
• breakdown
• collapse
• debacle
• destruction
• drubbing
• embarrassment
• failure
• killing
• loss
• massacre
• rout
• setback
• thrashing
• triumph