knock out
verb
RareNot in standard dictionaries
1
To strike or bump (someone or something) out.
2
To render unconscious, as by a blow to the head.
3
To put to sleep.
4
To fall asleep, especially suddenly.
5
To exhaust.
6
To impress, surpass or overwhelm (someone).
7
To defeat or kill (someone).
8
To cause a mechanism to become non-functional by damaging or destroying it.
9
To eliminate from a contest or similar.
10
To communicate (a message) by knocking.
#informal#obsolete#slang