Main entry: alarm, alarum, alert, warning signal
Definition: an automatic signal (usually a sound) warning of danger
Definition: a warning serves to make you more alert to danger
Definition: condition of heightened watchfulness or preparation for action
Usage: bombers were put on alert during the crisis
Definition: warn or arouse to a sense of danger or call to a state of preparedness
Usage: The empty house alarmed him; We alerted the new neighbors to the high rate of burglaries
Definition: engaged in or accustomed to close observation
Usage: 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
Main entry: awake, alert, alive
Definition: mentally perceptive and responsive
Usage: 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
Main entry: rattling, alert, spanking, snappy, zippy, brisk, merry, lively
Definition: quick and energetic
Usage: a brisk walk in the park; a lively gait; a merry chase; traveling at a rattling rate; a snappy pace; a spanking breeze