Open English Wordnet
Nouns
(n)alert, qui vivecondition of heightened watchfulness or preparation for action“bombers were put on alert during the crisis” (n)alert, alertinga warning serves to make you more alert to danger Verbs
(v)alarm, alertwarn 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” Adjectives
(a)alert, watchfulengaged 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” (s)alert, brisk, lively, merry, rattling, snappy, spanking, zippyquick 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” (s)alert, alive, awakementally 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”