catch (one) off (one's) guard(redirected from caught them off their guard)
catch (one) off (one's) guard
To engage, take advantage of, or seize upon one when one is not especially careful, vigilant, or prepared for danger or surprises. He's got a lot of tricky moves, so make sure he doesn't catch you off your guard! The soldiers moved in quickly, hoping to catch the enemy troops off their guard. I think I caught him off his guard when I told him I was resigning.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
catch someone off guardand catch one off (one's) guard
Fig. to catch a person at a time of carelessness. Tom caught Ann off guard and frightened her. She caught me off my guard, and my hesitation told her I was lying.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
catch off guard
see under off guard.
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.