on guard

(redirected from remain on guard)

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

*on (one's) guard (against someone or something)

alert against someone or something. (*Typically: be ~; keep ~; remain ~; stay ~.) Try to stay on guard against pickpockets. I am always on my guard. Be on guard when you go into the city.
See also: guard, on

on (one's) guard

Alert and watchful; cautious.
See also: guard, on