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. © 2024 Farlex, Inc, all rights reserved.
catch someone off guard
and catch one off (one's) guardFig. 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
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.