alert

Meanings

• condition of heightened watchfulness or preparation for action
  • "bombers were put on alert during the crisis"
• a warning serves to make you more alert to danger
• an automatic signal (usually a sound) warning of danger
• warn or arouse to a sense of danger or call to a state of preparedness
  • "We alerted the new neighbors to the high rate of burglaries"
• 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"
• quick and energetic
• mentally perceptive and responsive
  • "an alert mind"
  • "alert to the problems"

Synonyms

alarm, alarum, alerting, alive, awake, brisk, lively, merry, qui vive, rattling, snappy, spanking, warning signal, watchful, zippy