observant Synonyms

law-abiding observing practicing prudent quick quick-sighted regardful religious sharp sharp-witted pious observantine observational observative open-eyed perspicacious penetrating penetrative perceptive percipient shrewd sleepless smart leery all ears on the ball on guard on one's toes on the lookout overprotective unperplexed beady-eyed keen-eyed on the qui vive surveying thoughtful vigilant wakeful wary watchful wide-awake sharp-eyed unsleeping obedient acceptant chary circumspect clear-sighted clever cognizant