Definition of wakeful

• 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"
• (of sleep) easily disturbed; "in a light doze"; "a light sleeper"; "a restless wakeful night"
• marked by full consciousness or alertness; "worked every moment of my waking hours"