be on guard
be on guard
To be very attentive and alert, so as to avoid danger in a particular situation. A possessive pronoun can be used between "on" and "guard." When you're in the big city, you need to be on guard against criminals. I'm on my guard because I know the older guys on the team are going to prank me. I hope she's on her guard. Those trails can be a bit treacherous to climb.
See also: guard, on
Farlex Dictionary of Idioms.
- at one's leisure
- make (one's) money stretch
- stretch money
- not do (someone or oneself) any favors
- a bitter pill to swallow
- third person
- (Is) this taken?
- identify with
- rescue from
- rescue from (someone or something)