Alert

Part of speech: adjective, noun, verb

Pronunciation: /əˈlɜːt/

Definitions

1. A state of heightened awareness and readiness to respond quickly to potential danger or important events
2. A condition characterized by keen awareness and the ability to react promptly to significant occurrences or threats in the environment
3. An attentive state marked by readiness to perceive and respond effectively to critical information or dangers present in one's surroundings

Etymology: Before it meant "quick to notice," "alert" was a military call to attention. Its roots lie in Italian: "all'erta" literally meant "to the height," a phrase used by soldiers and lookouts told to climb to a high vantage point and keep watch. Italian "erta" referred to a lookout or tower, and the phrase carried the sense of being on guard from up high. The phrase passed into French as "à l'erte," and French speakers turned it into the adjective "alerte," meaning lively, watchful, or ready for action. English borrowed that adjective, and the sense of being poised and wary carried across with it. Over time the word settled into the everyday meaning of being quick to perceive or respond. English also later turned the adjective into a verb, so that to alert someone is to warn or make them aware. This verb use came from the adjective itself rather than from a separate borrowing, much as French developed its own verb "alerter" from the same root.

Synonyms: vigilant, watchful, attentive, aware, awake

Antonyms: unaware, oblivious, distracted, sleepy, indifferent