on one's guard


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Related to on one's guard: warship

on (one's) guard

Especially careful or vigilant; prepared for danger or surprises. He's got a lot of tricky moves, so be on your guard! Those trails can be a bit treacherous to climb. I just hope she's on her guard.
See also: guard, on
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

on one's guard

see under off guard.
See also: guard, on
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.
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