Meaning of ALERT in English
[alert] adj [It all' erta, lit., on the ascent] (1618) 1 a: watchful and prompt to meet danger or emergency b: quick to perceive and act
2: active, brisk syn see watchful, intelligent -- alert.ly adv -- alert.ness n
alert n (1796) 1: the state of readiness of those warned by an alert
2: an alarm or other signal of danger
3: the period during which an alert is in effect -- on the alert : on the lookout esp. for danger or opportunity alert vt (ca. 1868) 1: to call to a state of readiness: warn
2: to make aware of "~ed the public to the dangers of pesticides"
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012