'alert' definitions:

Definition of 'alert'

From: WordNet
adjective
Engaged in or accustomed to close observation; "caught by a couple of alert cops"; "alert enough to spot the opportunity when it came"; "constantly alert and vigilant, like a sentinel on duty" [syn: alert, watchful] [ant: unalert, unvigilant, unwatchful]
adjective
Quick and energetic; "a brisk walk in the park"; "a lively gait"; "a merry chase"; "traveling at a rattling rate"; "a snappy pace"; "a spanking breeze" [syn: alert, brisk, lively, merry, rattling, snappy, spanking, zippy]
adjective
Mentally perceptive and responsive;"an alert mind"; "alert to the problems"; "alive to what is going on"; "awake to the dangers of her situation"; "was now awake to the reality of his predicament" [syn: alert, alive(p), awake(p)]
noun
Condition of heightened watchfulness or preparation for action; "bombers were put on alert during the crisis" [syn: alert, qui vive]
noun
A warning serves to make you more alert to danger [syn: alert, alerting]
noun
An automatic signal (usually a sound) warning of danger [syn: alarm, alert, warning signal, alarum]
verb
Warn or arouse to a sense of danger or call to a state of preparedness; "The empty house alarmed him"; "We alerted the new neighbors to the high rate of burglaries" [syn: alarm, alert]

Synonyms of 'alert'

From: Moby Thesaurus