Wakeful has 4 different meanings across 1 category:
Adjective
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"
Awake; not sleeping.