knock out

Proposed by a contributor, not yet supported by evidence.

Sense 1

Meaning · English

to defeat or overwhelm someone

Nghĩa · Tiếng Việt

đánh bại hoặc áp đảo ai đó

Machine-translated — suggest a fix

Literally: hit someone so they fall unconscious
Where it’s used: Used Widespread English

Examples

The boxer's strong punch knocked out his opponent.

AI-drafted example auto-approved by rule (illustrative, not a corpus attestation)

Sources & notes

Listed in Wiktionary’s “English idioms” category (retrieved 2026-07-29); definition pending editorial review. Definition drafted by AI (@cf/meta/llama-3.3-70b-instruct-fp8-fast) and auto-approved by rule on 2026-07-31; pending editor spot-check.

Sense 2

Meaning · English

in racing parlance, to drive out of the quotations; as a KNOCKED-OUT favourite. Also to make bankrupt; as a KNOCKED-OUT backer or bookmaker. When a man cannot meet his engagements on the turf, he is said to be KNOCKED OUT.

Era: ca. 1874 (Victorian)

Where it’s used: Origin British & Irish English
Sources & notes

Historical definition reproduced from Hotten’s The Slang Dictionary (1874, public domain; Project Gutenberg #42108, retrieved 2026-07-31). Reflects the attitudes of its era.

Common questions

What does “knock out” mean?

to defeat or overwhelm someone Literally: hit someone so they fall unconscious

Is “knock out” formal or informal?

No register label has been reviewed yet — treat it as neutral and check the usage notes above.