1. Watchful; vigilant; active in vigilance.
2. Brisk; nimble; moving with celerity.
An alert young fellow. --Addison.
Syn: -- Active; agile; lively; quick; prompt.
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.
adj 1: very attentive or observant; "an alert and responsive baby
is a joy"; "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" [ant: unalert]
2: mentally responsive; "an alert mind"
3: not unconscious; especially having become conscious; "the
patient is now awake and alert" [syn: awake(p)]
4: (usually followed by `to') showing acute awareness; mentally
perceptive; "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" [syn: alive(p),
n 1: condition of heightened watchfulness or preparation for
action; "bombers were put on alert during the crisis"
[syn: qui vive]
2: a warning serves to make you more alert to danger [syn: alerting]
3: an automatic signal (usually a sound) warning of danger
[syn: alarm, warning signal, alarum]
v : 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" [syn: alarm]