alertness in WordNet English dictionary

1. a state of readiness to respond
   "alerting was indicated by the desynchronization of the EEG"
   alertness  alerting 
   
2. lively attentiveness
   alertness  sharp-sightedness  on the qui vive 
   
3. the process of paying close and continuous attention
   "wakefulness, watchfulness, and bellicosity make a good hunter"; "vigilance is especially susceptible to fatigue"
   watchfulness  wakefulness  vigilance  alertness