1. (

• argus-eyed ,
• open-eyed ,
• vigilant ,
• 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" ;

2. (

• light ,
• wakeful

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

3. (

• waking ,
• wakeful

) marked by full consciousness or alertness; "worked every moment of my waking hours" ;