1. Carefully observant or attentive; on the lookout for possible danger
   - argus-eyed, open-eyed, vigilant 
2. (of sleep) easily disturbed
   "a restless wakeful night"
   - light 
3. Marked by full consciousness or alertness
   - waking

See also: alert, awake, shallow, wakefulness, watchful

Encyclopedia: Wakeful

• vitamin
• vitamin A
• vitamin A1
• vitamin A2
• vitamin B
• vitamin B complex
• vitamin B1
• vitamin B12
• vitamin B2
• vitamin B6
• vitamin Bc
• vitamin C
• vitamin D
• vitamin E
• vitamin G
• vitamin H
• vitamin K
• vitamin K1
• vitamin K3
• vitamin M
• vitamin P
• vitamin pill
• vitamin-deficiency diet
• vitaminise
• vitaminize