Definition of "alert" in English

adjective

1. Attentive; awake; on guard.

2. (obsolete) brisk; nimble; moving with celerity.

noun

1. An alarm.

2. A notification of higher importance than an advisory.

3. (military) A state of readiness for potential combat.

   • an airborne alert; ground alert

4. (computing) Synonym of bell (“bell character”).

verb

1. To give warning to.