alertness

from WordNet (r) 3.0 (2006)

alertness
    n 1: 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}]
    2: a state of readiness to respond; "alerting was indicated by
       the desynchronization of the EEG" [syn: {alertness},
       {alerting}]
    3: lively attentiveness [syn: {alertness}, {sharp-sightedness},
       {on the qui vive}]

from The Collaborative International Dictionary of English v.0.48

Alertness \A*lert"ness\, n.
   The quality of being alert or on the alert; briskness;
   nimbleness; activity.
   [1913 Webster]