Definition of watchful

• 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"
• experiencing or accompanied by sleeplessness; "insomniac old people"; "insomniac nights"; "lay sleepless all night"; "twenty watchful, weary, tedious nights"- Shakespeare