knock out

Idioms  

1. Also, knock out cold . Render unconscious by a blow or some other means. For example, It was just a swinging door, but it knocked her out , or Just one of those sleeping pills can knock you out cold . [Late 1500s]

2. Make tired, exhaust, as in That sightseeing tour knocked me out .

3. Render useless or inoperative, as in The storm knocked out the power .

4. See knock off , def. 2.

5. See knock oneself out .

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Example Sentences

So don’t expect $28 tickets for finals or knock out rounds to the most in-demand sports including women’s artistic gymnastics, basketball, swimming or track and field to be sold at all.

From Los Angeles Times • Apr. 15, 2026

Second, do we need to have the ability to knock out all of their missile sites in order to deter nuclear war?

From Slate • Feb. 3, 2026

Faraaz, the youngest of the group at 22, was the first to be voted out around the firepit during the endgame, leaving Rachel and Steven to team up to knock out Jack.

From BBC • Jan. 23, 2026

A single freeze-up can knock out an entire weapons platform or immobilize a convoy.

From The Wall Street Journal • Dec. 27, 2025

The massive disturbances to the ionosphere would knock out communications systems everywhere, so survivors would have no idea what was happening elsewhere or where to turn.

From "A Short History of Nearly Everything" by Bill Bryson