knock somebody 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.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
knock somebody ˈdead(spoken) impress somebody very much: You look fabulous — you’ll knock ’em dead tonight.
Farlex Partner Idioms Dictionary © Farlex 2017