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. 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

Other Word Forms

• alertly adverb
• alertness noun
• hyperalert adjective
• unalerted adjective

Word History and Origins

Origin of alert¹

First recorded in 1590–1600; 1940–45 alert for def. 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.

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

But in May 2014, Indyke asked a bank employee a question that revealed his real concern: How often could he withdraw cash without triggering an alert?

Read more on The Wall Street Journal

Bonta said the state’s Fair Political Practices Commission also has alerted him that it received a complaint against him.

Read more on Los Angeles Times

Feeling "brighter, more alert and more connected" has real physiological effects.

Read more on BBC

Still, while it may be tricky, they say there are signs listeners can be alert to.

Read more on BBC

Northern Australia is on high alert as a tropical cyclone barrels down on the state, as authorities warn the worst of the storm will strike on Saturday.

Read more on Barron's

Related Words

• active 
• bright 
• careful 
• intelligent 
• observant 
• perceptive 
• sharp 
• vigilant 
• wary 
• watchful 
• wired 
• wise 

When To Use

What does alert mean?

An alert is a warning or alarm, especially an alarm about dangerous weather or a military attack, as in The National Weather Service has alerts for tornadoes, hurricanes, Nor’easters, and other severe weather occurrences.Alert is also an attitude of readiness or caution, as in Tina was on alert for news of her son’s acceptance into college.Alert describes being fully attentive or wide awake, as in Sabine needs to be awake for several hours before she is alert and ready to work. You can be alert to the people and objects surrounding you. When you are alert, you’re ready to act or react instead of being surprised. But you can also be alert to concepts, ideas, and trends, ready to react to a change in others’ thoughts or to a change in the market.To alert means to advise or to warn, as with an alert. For example, your teacher might alert you that your big project is due soon, while a police department might alert the public about a dangerous person on the streets.Example: Alert the security team of the incident and then head home.