knock (one) cold

knock (one) cold

1. To strike someone so hard that they lose consciousness. Yikes, that punch knocked the boxer cold.
2. To strongly impress someone. I'm sure she'll knock them cold in the audition. Your design is going to knock the judges cold. They're going to swoon over it.
See also: cold, knock
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

knock someone cold

 
1. Fig. to render someone unconscious by a violent blow. One swipe, and he knocked him cold. If you touch her again, I'll knock you cold.
2. and knock someone dead Fig. to put on a stunning performance or display for someone. (Someone is often replaced by 'em from them.) This band is going to do great tonight. We're going to knock them dead. "See how your sister is all dressed up!" said Bill. "She's going to knock 'em cold."
See also: cold, knock
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.

knock cold

To render unconscious; knock out.
See also: cold, knock
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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