What is the meaning of wakeful?

adjective

• Carefully observant or attentive; on the lookout for possible danger.
  • usage: "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"
  • synonyms: argus-eyed, open-eyed, vigilant
• Of sleep. ( easily disturbed)
  • usage: "in a light doze"; "a light sleeper"; "a restless wakeful night"
  • synonyms: light
• Marked by full consciousness or alertness.
  • usage: "worked every moment of my waking hours"
  • synonyms: waking