[syn: watchfulness, wakefulness, vigilance, alertness]
The Collaborative International Dictionary of English v.0.48:
Wakeful \Wake"ful\, a.
   Not sleeping; indisposed to sleep; watchful; vigilant.
   [1913 Webster]
         Dissembling sleep, but wakeful with the fright.
                                                  --Dryden.
   [1913 Webster] -- Wake"ful*ly, adv. -- Wake"ful*ness, n.
   [1913 Webster]
WordNet (r) 3.0 (2006):
wakefulness
    n 1: a periodic state during which you are conscious and aware
         of the world; "consciousness during wakefulness in a sane
         person is pretty well ordered and familiar"
    2: a temporary state in which you are unable (or unwilling) to
       sleep; "accept your wakefulness and sleep in its own contrary
       way is more likely to come" [syn: wakefulness,
       sleeplessness] [ant: drowsiness, sleepiness,
       somnolence]
    3: the process of paying close and continuous attention;
       "wakefulness, watchfulness, and bellicosity make a good
       hunter"; "vigilance is especially susceptible to fatigue"
       [syn: watchfulness, wakefulness, vigilance,
       alertness]