definition of
alert

[1] #1 alert v. [alarm] 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". wn

[2] #2 alert a. [watchful] 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". wn

[3] #3 alert n. [qui vive] condition of heightened watchfulness or preparation for action; "bombers were put on alert during the crisis". wn

[4] #4 alert n. [alerting] a warning serves to make you more alert to danger. wn

[5] #5 alert s. [brisk, lively, merry, rattling, snappy, spanking, zippy] 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". wn