alert

Synonyms: active all ears bright cagey careful circumspect clever fast on the draw good hands heads up heedful hip intelligent jazzed observant on guard on one’s toes on the ball on the job on the lookout on the qui vive perceptive psyched up quick ready sharp spirited switched on vigilant wary watchful wide-awake wired wise with it

Antonyms: asleep drowsy inattentive lethargic sluggish unobservant weary

Synonyms: admonition alarm flap high sign mayday sign signal siren sos tip off wink

Synonyms: alarm flag forewarn give the high sign inform notify put on guard signal tip tip off wave flag