alert

[ uh-lurt ]

adjective

1. fully aware and attentive; wide-awake; keen:

   She had an alert mind.

   Synonyms: observant, wary, awake

   Antonyms: unaware

2. swift; agile; nimble.

   Synonyms: spirited, sprightly, active, quick, lively, brisk

noun

1. an attitude of vigilance, readiness, or caution, as before an expected attack.
2. a warning or alarm of an impending military attack, a storm, etc.:

   We'd just boarded the bus when the alert sounded.

3. the period during which such a warning or alarm is in effect.

verb (used with object)

1. to warn (troops, ships, etc.) to prepare for action.
2. to warn of an impending raid, attack, storm, etc.:

   The radio alerted coastal residents to prepare for the hurricane.

3. to advise or warn; cause to be on guard:

   to alert gardeners to the dangers of some pesticides.

alert

/ əˈlɜːt /

adjective

1. vigilantly attentive

   alert to the problems

2. brisk, nimble, or lively

noun

1. an alarm or warning, esp a siren warning of an air raid
2. the period during which such a warning remains in effect
3. on the alert
   1. on guard against danger, attack, etc
   2. watchful; ready

      on the alert for any errors

verb

1. to warn or signal (troops, police, etc) to prepare for action
2. to warn of danger, an attack, etc

Derived Forms

• aˈlertly, adverb
• aˈlertness, noun

Other Words From

• a·lertly adverb
• a·lertness noun
• hyper·a·lert adjective
• una·lerted adjective

Word History and Origins

Origin of alert¹

First recorded in 1590–1600; 1940–45 alert fordef 4; from Italian all'erta, equivalent to all ( a ) “to, on the” + erta “lookout, watchtower,” originally feminine of erto, past participle of ergere from Latin ērigere to erect

Word History and Origins

Origin of alert¹

C17: from Italian all'erta on the watch, from erta lookout post, from ergere to build up, from Latin ērigere; see erect

Idioms and Phrases

Idioms

1. on the alert, on guard against danger; in readiness; vigilant:

   The state police are on the alert for an escaped convict believed to be in the area.

More idioms and phrases containing alert

see on the alert .

Synonym Study

Alert, vigilant, watchful imply a wide-awake attitude, as of someone keenly aware of their surroundings. Alert describes a ready and prompt attentiveness together with a quick intelligence: The tourist was alert and eager to see the sights. Vigilant suggests some immediate necessity for keen, active observation, and for continuing alertness: Knowing the danger, the scout was unceasingly vigilant. Watchful suggests carefulness and preparedness: A stakeout requires watchful waiting.

Example Sentences

In addition to speed reduction, other options to reduce whale-ship strikes include changing vessel routings away from where whales are located, or creating alert systems to notify authorities and mariners when whales are nearby.

From Science Daily

This signal serves as an alert for medical personnel, immediately drawing attention to potentially hazardous circumstances.

From Science Daily

Several users on X, formerly Twitter, posted screenshots of an alert telling them "please check your entries and try again" when attempting to log in.

From BBC

I was able to sort of stretch so much more because I was kept so alert by the job at hand.

From Los Angeles Times

The researchers engineered yeast to act as single-celled drug factories and produce immune checkpoint inhibitors -- anticancer drugs that alert immune cells to the presence of cancer cells.

From Science Daily

Related Words

• alarm
• signal