Alert
Alert (ȧ*lẽrt") , adjective
[French alerte, earlier à l'erte on the watch, from Italian all' erta on the watch, prop. (standing) on a height, where one can look around; erta a declivity, steep, erto steep, past participle of ergere, erigere, to erect, raise, Latin erigere. See Erect.]
1.
Watchful; vigilant; active in vigilance.
2.
Brisk; nimble; moving with celerity.
An alert young fellow.
Alert , noun
(Military) An alarm from a real or threatened attack; a sudden attack; also, a bugle sound to give warning.
We have had an alert.
Collocations (1)
On the alert , on the lookout or watch against attack or danger; ready to act.