throw someone for a loop

throw (one) for a loop

To shock, surprise, astonish, or bewilder one. The end of that trick always throws the audience for a loop. I love watching their faces as they desperately try to figure it out. It really threw Stu for a loop when Olivia announced she was leaving the company.

See also: for, loop, throw

Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

throw someone for a loop

or

knock someone for a loop

AMERICAN, INFORMAL

If someone or something throws you for a loop or knocks you for a loop, they shock you or surprise you very much. If Kravis's offer had thrown him for a loop, Johnson wasn't letting it show. She was wearing a top hat, the sight of which knocked Jamie for a loop.

See also: for, loop, someone, throw

Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012

throw (or knock) someone for a loop

surprise or astonish someone; catch someone off guard. North American

See also: for, loop, someone, throw

Farlex Partner Idioms Dictionary © Farlex 2017

throw someone for a loop

tv. to confuse or surprise someone. Don’t let this question throw you for a loop.

See also: for, loop, someone, throw

McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.