1.condition of heightened watchfulness or preparation for action;
bombers were put on alert during the crisis
2.a warning serves to make you more alert to danger
3.an automatic signal (usually a sound) warning of danger
4.very attentive or observant;
an alert and responsive baby is a joy
5.mentally responsive;
an alert mind
6.not unconscious; especially having become conscious;
the patient is now awake and alert
7.(usually followed by `to') showing acute awareness; mentally perceptive;
alert to the problems
1.warn or arouse to a sense of danger or call to a state of preparedness;
The empty house alarmed him