alertness
1. [ noun ] the process of paying close and continuous attention
Synonyms: vigilance watchfulness
Related terms: attention jealousy
2. [ noun ] a state of readiness to respond
Synonyms: alerting
Examples:

"alerting was indicated by the desynchronization of the EEG"

Related terms: arousal
3. [ noun ] lively attentiveness
Synonyms: on_the_qui_vive
Related terms: attentiveness
Similar spelling:   alertly