ko

The word “ko” means in the board game Go, a repeating capture situation where a single stone could be taken back and forth forever, so special rules stop it. In plain terms, in Go, a repeated-capture rule; in boxing slang, to knock someone out cold.

“Ko” is pronounced KOH (/ˈkəʊ/ in IPA).

Here is “ko” used in a sentence: “She avoided starting a ko fight because she was already ahead on the board.”

Depending on how it is used, “ko” can be a noun and a verb.

The word “ko” comes from Japanese. The Go sense is borrowed from the Japanese word 劫 (kō); the "knock out" verb comes from the abbreviation K.O.

“Ko” is an uncommon word in modern English.

“Ko” has 2 distinct senses listed in this dictionary. The most common is: in the board game Go, a repeating capture situation where a single stone could be taken back and forth forever, so special rules stop it.

In sports and fighting contexts, KO refers to knocking someone unconscious. It is typically written in capital letters as "KO" as an abbreviation.

A ko in Go is a repeating capture situation where a single stone could be taken back and forth forever, so the game uses special rules to stop this endless cycle. It is a Go-specific term distinct from the boxing sense of KO.

Without a special rule, a ko would allow players to capture the same single stone back and forth indefinitely, since it is a repeating capture situation. Go's ko rule prevents this endless loop so the game can progress.

The Go term is generally written in lowercase as "ko," while the boxing and fighting sense is usually capitalized as "KO" as an abbreviation. Context makes clear which meaning is intended.