knock someone dead

knock (one) dead

To strongly impress one. Often used as an imperative to give encouragement. Good luck on the audition! Knock 'em dead, kid! Your design is going to knock the judges dead. They're going to swoon over it.
See also: dead, knock
Farlex Dictionary of Idioms.

knock someone dead

greatly impress someone. informal
1991 Julia Philips You'll Never Eat Lunch In This Town Again I'm good at public speaking. I've been knocking them dead at seminars.
See also: dead, knock, someone
Farlex Partner Idioms Dictionary

knock someone dead

tv. to put on a stunning performance or display for someone. She knocked us dead with her stunning performance.
See also: dead, knock, someone
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • knock (one) dead
  • knock dead
  • knock 'em dead
  • knock somebody dead
  • knock about with (one)
  • knock up
  • knocked up
  • knock (someone) down with a feather, to
  • knock one back
  • knock something back