knock someone off—
1. make a person fall with a push:
- You’re not safe on that ladder; a branch could knock you off.
2. (Sport) defeat a competitor:
- If he can knock off the next two opponents, he could get into the last part of the competition.
3. (sl.) kill a person:
- I don’t want to knock the old man off; can’t we just tie him up to keep him quiet?
Note: The expression does not fully correlate in meaning with the phrase knock someone off his feet—
1. = knock someone off 1:
- The sudden explosion of light, power, and thunder knocked me off my feet and I landed hard on my back.
2. (coll.) have a powerful emotional effect on a person:
- In addition to the perfect weather, the smell of the trees and good country air nearly knocked me off my feet.
knock someone out—
1. make a person unconscious by hitting him:
- Scott’s reputation is excellent, and the managers fear that he has been knocked out and robbed.
2. = knock someone off 2:
- Our team got through to the second part of the competition before they were knocked out.
3. (coll.) tire a person very much (through overwork):
- Hours of gardening in the sun have quite knocked me out.
Cf.: knock oneself out—(coll.) work very hard; make an extra effort to accomplish smth.:
- We thank the one person who knocked himself out making sure we enjoyed ourselves.
4. (coll., also: knock someone dead) put on a stunning performance; have a powerful emotional effect on a person:
- I hadn’t heard of her show beforehand, but watched it immediately and she knocked me out.