Definition of "knock out" in English

Verb

To strike or render unconscious To strike or bump (someone or something) out.
- I accidentally knocked out the glass in my picture frame.
- The boxer knocked out his opponent in the third round.
- The allergy pill knocked him out for a good three hours.
- Running errands all day really knocked him out.
- The antitank gun knocked out the enemy tank.
To strike or bump (someone or something) out.
- I accidentally knocked out the glass in my picture frame.
To render unconscious, as by a blow to the head.
- The boxer knocked out his opponent in the third round.
To put to sleep.
- The allergy pill knocked him out for a good three hours.
To fall asleep, especially suddenly.
To exhaust.
- Running errands all day really knocked him out.
To impress, surpass or overwhelm (someone).
To defeat or kill (someone).
To cause a mechanism to become non-functional by damaging or destroying it.
- The antitank gun knocked out the enemy tank.
To eliminate from a contest or similar.
To communicate (a message) by knocking.
- The prisoner knocked out a message on the wall for the prisoner in the adjoining cell.
To complete, especially in haste; knock off.
- They knocked out the entire project in one night.
To lose the scent of hounds in fox-hunting.
To leave college after hours—after half-past ten at night when the doors have been locked.
To obtain or earn (something, often money or food).
To sell.