wakeful

英 ['weɪkfʊl; -f(ə)l] 美['wekfl]

1. carefully observant or attentive; on the lookout for possible danger;: "a policy of open-eyed awareness"; "the vigilant eye of the town watch"; "there was a watchful dignity in the room"; "a watchful parent with a toddler in tow"

2. (of sleep) easily disturbed;: "in a light doze"; "a light sleeper"; "a restless wakeful night"