alert

adjective
\ ə-ˈlərt How to pronounce alert (audio) \

Definition of alert

 (Entry 1 of 3)

1a : watchful and prompt to meet danger or emergency an alert guard trying to stay alert to possible problems
b : quick to perceive and act mentally alert
2 : active, brisk elicited an alert response

alert

noun

Definition of alert (Entry 2 of 3)

1 : a state of careful watching and readiness especially for danger or opportunity on 24-hour alert
2a : an alarm or other signal of danger traffic alerts They sounded the alert.
b : an urgent notice … an alert to parents … about new immunization requirements.— Ann Schrader
3 : the period during which an alert is in effect
on the alert
: looking for or expecting something (such as danger or an opportunity) Drivers need to be on the alert for icy condition. always on the alert for a good bargain

alert

verb
alerted; alerting; alerts

Definition of alert (Entry 3 of 3)

transitive verb

1 : to call (someone) to a state of readiness : warn alerted the school board of a possible teachers' strike alert the authorities
2 : to make (someone) aware of something alerted the public to the dangers of pesticides

Keep scrolling for more

Other Words from alert

Adjective

alertly adverb
alertness noun

Synonyms & Antonyms for alert

Synonyms: Adjective

Synonyms: Noun

Synonyms: Verb

Antonyms: Adjective

Visit the Thesaurus for More 

Choose the Right Synonym for alert

Adjective

watchful, vigilant, wide-awake, alert mean being on the lookout especially for danger or opportunity. watchful is the least explicit term. the watchful eye of the department supervisor vigilant suggests intense, unremitting, wary watchfulness. eternally vigilant in the safeguarding of democracy wide-awake applies to watchfulness for opportunities and developments more often than dangers. wide-awake companies latched onto the new technology alert stresses readiness or promptness in meeting danger or in seizing opportunity. alert traders anticipated the stock market's slide

intelligent, clever, alert, quick-witted mean mentally keen or quick. intelligent stresses success in coping with new situations and solving problems. an intelligent person could assemble it fast clever implies native ability or aptness and sometimes suggests a lack of more substantial qualities. clever with words alert stresses quickness in perceiving and understanding. alert to new technology quick-witted implies promptness in finding answers in debate or in devising expedients in moments of danger or challenge. no match for his quick-witted opponent

Examples of alert in a Sentence

Adjective An alert guard stopped the robbers. He was tired and had trouble staying alert while he was driving. She wasn't mentally alert enough to answer the questions. An alert watchdog guarded the door. Noun They sounded an alert when enemy planes were approaching the city. Medical officials have put out an alert to hospitals to look out for the virus. The government has issued a terrorism alert. Verb Several neighbors alerted the authorities when they noticed strangers acting suspiciously. The governor alerted island residents that a hurricane was coming. The teacher alerted the students that tests would be given the next day.
See More
Recent Examples on the Web: Adjective The demonstrations don’t have a leader, but participants have mobilized crowds using phone calls, texts, live-streaming, messaging apps like Signal and social-media websites to exchange plans and alert fellow protesters. Niharika Mandhana, WSJ, "Myanmar Protests: Hundreds of Thousands Take to the Streets During Strike to Oppose Coup," 22 Feb. 2021 The second measure in the alert tracking system is the daily average of new cases, over the previous seven days. Rich Exner, cleveland, "This is how dramatically Greater Cleveland counties have improved in every measure in Ohio’s coronavirus alert system," 19 Feb. 2021 The connection with Nelson brought everything together – a keen Rodgers audible, a deft blitz pickup, an alert route adjustment and a catch-and-run that tied it all together. jsonline.com, "'We came out like a whirlwind tornado'," 19 Feb. 2021 Ohio's new coronavirus cases have fallen sharply in the past month, but the state's COVID-19 alert map has not changed in three weeks. Jackie Borchardt, The Enquirer, "COVID-19 cases are going down in Ohio, so why is the county heat map still red?," 19 Feb. 2021 Expressing his outrage via email, Schaefer urged the city to remove the sign or, at the very least, accent it with blinking lights to more effectively alert pedestrians. San Diego Union-Tribune, "Column: Is the Spruce Street suspension bridge open or closed?," 19 Feb. 2021 On the one hand, members of the representative community demand authenticity and fidelity to the source material, alert for any hint of pandering to the white gaze. Jean Chen Ho, Harper's BAZAAR, "Bling Empire and the Energizing Potential of Asian-American Mediocrity," 17 Feb. 2021 And many people are wearing masks, so drivers are less alert when a masked person approaches them, giving a potential thief the element of surprise. Aarian Marshall, Wired, "Carjackings Are Up—and Gig Workers Are Getting Victimized," 12 Feb. 2021 An alert plant worker saw the hacker’s efforts happening live on a computer’s desktop and immediately changed the lye levels back to safe levels, Pinellas County Sheriff Bob Gualtieri said in a press conference on Feb. 8. Grant Gross, Washington Examiner, "Hacker attempts to poison Florida city’s water supply," 11 Feb. 2021 Recent Examples on the Web: Noun Quintana Roo’s stoplight alert system, which is assessed weekly on Thursdays and takes effect on the following Monday, was lowered from orange to yellow status. Washington Post, "Mexico eases coronavirus restrictions in popular tourist cities ahead of spring break," 26 Feb. 2021 On Thursday morning, 10 states are on alert from California to Montana with damaging winds, heavy snow and avalanche danger as a winter storm warning continues for Denver early today. Max Golembo, ABC News, "Stormy weather pattern on the way for the West and the South," 25 Feb. 2021 But then Chad admits Hiram gave him a job offer to manage Sodale properties, which sets off her red flag alert because her Hubby and Daddykins have been talking behind her back. Sydney Bucksbaum, EW.com, "Riverdale recap: Back to school for more epic highs and lows of high school football," 25 Feb. 2021 To quell residents’ frustrations with securing COVID-19 vaccines, San Antonio has launched a text alert service that will notify users when appointments to receive the shots become available. San Antonio Express-News, "Express Briefing: SAWS contract puts official's scrutiny in doubt," 25 Feb. 2021 AltumView Systems smart medical alert system, which includes the smart visual sensor, cloud server and mobile application. Mark Minevich, Forbes, "Surviving Covid-19 Does Not Mean Thriving, But Advanced Technology Could Promote A Better Life Experience & Recovery," 24 Feb. 2021 Seven would be the lowest level – yellow, or level 1 alert – instead of red: Geauga. Holmes. Knox. Miami. Ottawa. Pickaway. Jackie Borchardt, The Enquirer, "COVID-19 cases are going down in Ohio, so why is the county heat map still red?," 19 Feb. 2021 The Mount Sinai researchers hope to eventually add a real-time alert element to their research using the Warrior Watch Study App, which collects data from the Apple Watch and Apple Health app. Mike Snider, USA TODAY, "COVID-19 detection: Could your Apple Watch or Fitbit help slow the coronavirus pandemic?," 19 Feb. 2021 The pop diva loves the game of mystery and has been keeping fans on full alert with tweets teasing to the project. Kendall Trammell, CNN, "Watch more than just 'Judas and the Black Messiah' this Black History Month," 18 Feb. 2021 Recent Examples on the Web: Verb Before the vote, Moreno and Joe Giarrusso also urged Entergy to create programs to alert customers in real time about their power use. Jessica Williams, NOLA.com, "After power bills spike in New Orleans, City Council directs Entergy to suspend shutoffs," 2 Feb. 2021 So Howland Forrest passed along a note to alert Bjerkaas about the news of Bryant and his daughter. USA Today, "Church in the Canyon became grieving site for Lakers fans," 24 Jan. 2021 In their first days in office, Trump’s team was forced to rewrite executive orders by court order and aides took days to figure out how to use the White House intercom to alert press about events. Tim Darnell, ajc, "What will Joe Biden do on his first day as president?," 20 Jan. 2021 Yet, the lawsuit said, Wheeler didn’t alert the authorities. Peggy O’hare, ExpressNews.com, "Second lawsuit filed against Wheeler for Anaqua Springs shooting deaths," 19 Jan. 2021 Kennedy also said the fact that the department doesn’t alert prosecutors to deputies who do not fall under the transparency law is problematic. Leila Miller Staff Writer, Los Angeles Times, "Sheriff defied court orders, did not name deputies with histories of misconduct. It was a costly decision," 17 Oct. 2020 The White House didn’t alert the pool reporters responsible for following the president’s movements about the trip ahead of time. Andrew Restuccia, WSJ, "Trump Exits Walter Reed Isolation in SUV to Greet Supporters," 5 Oct. 2020 The city’s gunfire detection system – Shot Spotter – did not alert to any shots fired in the area. Carol Robinson | Crobinson@al.com, al, "Man found shot to death in middle of southwest Birmingham street," 31 Aug. 2020 Some questioned why the Bucks did not alert them about their plans ahead of time. Mark Medina, USA TODAY, "How NBA players union leadership navigated conversations on playoff resumption, increasing social justice work," 29 Aug. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'alert.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of alert

Adjective

1618, in the meaning defined at sense 1a

Noun

1801, in the meaning defined at sense 1

Verb

circa 1868, in the meaning defined at sense 1

History and Etymology for alert

Adjective

borrowed from French alerte, going back to Middle French a l'herte "on guard, on the watch," borrowed from Italian all'erta, originally in the collocation stare all'erta "to be on the watch," literally, "to be on the height" (with erta "height, hill, steep ascent," noun derivative from feminine of erto, past participle of ergere "to raise, elevate," going back to Vulgar Latin *ērgere, by syncope from Latin ērigere) — more at erect entry 1

Note: The earliest citation for the word in the Oxford English Dictionary suggests direct borrowing from Italian, or at least recognition of an Italian source: "In this place the Prince [of Orange] finding his rutters [cavalry soldiers] alert, (as the Italians say) with aduise of his valiant brother, hee sent his Trumpets to D. d' Alua…." (Sir Roger Williams, The Actions of the Lowe Countries, London, 1618, p. 27).

Noun

noun derivative of alert entry 1 (or borrowed from French alerte, derivative of alerte, adjective)

Verb

verbal derivative of alert entry 1 or alert entry 2

Keep scrolling for more

Learn More about alert

Statistics for alert

Last Updated

1 Mar 2021

Cite this Entry

“Alert.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/alert. Accessed 2 Mar. 2021.

Style: MLA
MLA Chicago APA Merriam-Webster

Keep scrolling for more

More Definitions for alert

alert

adjective

English Language Learners Definition of alert

 (Entry 1 of 3)

: able to think clearly and to notice things

alert

noun

English Language Learners Definition of alert (Entry 2 of 3)

: something (such as a message or loud sound) that tells people there is some danger or problem : an alarm or signal of danger
: the state of being ready for something you have been warned about (such as an attack)

alert

verb

English Language Learners Definition of alert (Entry 3 of 3)

: to give (someone) important information about a possible problem, danger, etc. : to warn (someone)
: to make (someone) aware of something

alert

adjective
\ ə-ˈlərt How to pronounce alert (audio) \

Kids Definition of alert

 (Entry 1 of 3)

1 : watchful and ready especially to meet danger But he was alert at night, too, on the road, always listening intently …— Lois Lowry, The Giver
2 : quick to understand and act An alert reader noticed the error in grammar.

Other Words from alert

alertly adverb The prairie dog sat alertly beside the opening of its burrow.

alert

noun

Kids Definition of alert (Entry 2 of 3)

1 : an alarm or signal of danger The police issued an alert.
2 : the period during which an alert is in effect We stayed indoors during the alert.
on the alert
: watchful against danger … the remark had set us all on the alert, straining ears and eyes …— Robert Louis Stevenson, Treasure Island

alert

verb
alerted; alerting

Kids Definition of alert (Entry 3 of 3)

: to make aware of a need to get ready or take action : warn The siren alerted us that a tornado was approaching.

Keep scrolling for more

More from Merriam-Webster on alert

Thesaurus: All synonyms and antonyms for alert

Nglish: Translation of alert for Spanish Speakers

Britannica English: Translation of alert for Arabic Speakers

Comments on alert

What made you want to look up alert? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

Test Your Vocabulary

February 2021 Words of the Day Quiz

  • squirrel in winter
  • Which is a synonym of perdure?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!