A*lert" (#), a. [F. alerte, earlier a l'erte on the watch, fr. It. all' erta on the watch, prop. (standing) on a height, where one can look around; erta a declivity, steep, erto steep, p. p. of ergere, erigere, to erect, raise, L. erigere. See Erect.]


Watchful; vigilant; active in vigilance.


Brisk; nimble; moving with celerity.

An alert young fellow. Addison.

Syn. -- Active; agile; lively; quick; prompt.


© Webster 1913.

A*lert", n. Mil.

An alarm from a real or threatened attack; a sudden attack; also, a bugle sound to give warning.

"We have had an alert."


On the alert, on the lookout or watch against attack or danger; ready to act.


© Webster 1913.