alert

adjective

\ ə-ˈlərt

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

Other Words from alert Synonyms & Antonyms Choose the Right Synonym More Example Sentences Learn More about alert

Keep scrolling for more

Synonyms & Antonyms for alert

Synonyms: Adjective

Argus-eyed, attentive, awake, observant, open-eyed, tenty (also tentie) [Scottish], vigilant, watchful, wide-awake

Synonyms: Noun

admonishment, admonition, alarm (also alarum), caution, forewarning, heads-up, notice, warning

Synonyms: Verb

advise, caution, forewarn, wake, warn

Antonyms: Adjective

asleep

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.

Recent Examples on the Web: Adjective

According to Everyday Health, meditation can improve concentration, reduce stress, prevent cognitive decline, and keep your brain healthy and alert as you age. — Jessica Leigh Mattern, Woman's Day, "30 Fun Things to Do By Yourself in Your Lifetime," 3 Jan. 2019 The students also reported feeling less sleepy and more alert. — Angela Chen, The Verge, "Why we might want the school day to start later," 12 Dec. 2018 The result is military personnel more alert, focused, and better able to do their jobs. — Kyle Mizokami, Popular Mechanics, "A New Electronic Device Could Cure the Military's Big Motion Sickness Problem," 22 Nov. 2018 Hence, if software can drive as well as the average sober, alert human driver, its widespread use would save thousands of lives per year. — Timothy B. Lee, Ars Technica, "Car crashes killed 37,133 people in the US in 2017," 3 Oct. 2018 In 2016 IceCube's operators set up an alert service, with the hope of getting more telescopes at different wavelengths involved in the hunt. — Daniel Clery, Science | AAAS, "Ghostly particle caught in polar ice ushers in new way to look at the universe," 12 July 2018 Those using drugs should not do so alone, the alert states. — Terry Demio, Cincinnati.com, "Overdoses surging in Hamilton County, public health issues alert," 11 July 2018 Drivers are urged to be alert of construction workers. — Suzanne Baker, Naperville Sun, "Road and ramp repairs on I-88 between Naperville and Oak Brook start this week," 10 July 2018 In addition, the agency is looking for volunteers to join its storm alert team. — Sergio Carmona, Jewish Journal, "Jewish organizations step-up hurricane preparedness efforts," 6 July 2018

Recent Examples on the Web: Noun

Earlier this year, an update in the Jacquard platform introduced a handful of other functions, like support for ride-sharing alerts and pin drops on a map to save locations. — Dani Deahl, The Verge, "Google and Levi’s smart jacket can now warn you if you’re about to leave your phone behind," 9 Dec. 2018 And sign up for email or text alerts on your accounts so you're notified about major activity, purchases, withdrawals, etc. — Teresa Dixon Murray, cleveland.com, "Malley's Chocolates' website hacked, 3,400 online customers' card information breached," 10 May 2018 Just subscribe here: Get breaking news alerts on Apple News Don’t want to keep hitting the refresh button? — Dan Frommer, Recode, "Code Commerce, our summit on the future of retail, is almost here. Here’s how to follow along.," 14 Sep. 2018 The throttle and gearbox are plenty alert and when commanded the six will quietly pull its heart out. — Dan Neil, WSJ, "2019 Mercedes-Benz CLS: A Move Toward Electrification," 3 Aug. 2018 Most of southwest California is under a red flag warning, the alert for dangerous fire weather. — Jason Samenow, Washington Post, "Monster heat dome threatens temperature records today in Southern California," 6 July 2018 The agency sent the false alert at 8:07 a.m. on Jan. 13. — CBS News, "Workers of Hawaii agency that sent false missile alert allegedly slept on duty," 28 June 2018 These antioxidant-like compounds may help counteract chronic inflammation, a physiological state where your body's cells stay on high alert due to a lingering or past threat. — Caroline Picard, Good Housekeeping, "The 5 Best Health Benefits of Ginger Water," 11 Jan. 2019 But researchers are on alert now in an effort to help pregnant women across the globe stay ahead of the curve. — Macaela Mackenzie, Glamour, "Rift Valley Fever Could Be the Next Global Health Crisis For Pregnant Women," 10 Jan. 2019

Recent Examples on the Web: Verb

In a Facebook post today, the brothers alerted their 973,573 followers that there's a scam circulating wherein someone who is decidedly not from their company tries to offer their services. — Kaitlin Menza, House Beautiful, "There's A Property Brothers Scam Circulating On The Internet," 25 Jan. 2019 The employee alerted a state trooper working an overtime assignment at the MDOT Motor Vehicle Administration location in Glen Burnie. — Fox News, "Man waiting for driving test found with gun, drugs in vehicle, cops say," 2 Oct. 2018 Police alerted the Federal Aviation Administration and the National Transportation Safety Board. — Christine Dempsey, courant.com, "Burlington Pilot Died In Plainville Plane Crash, Police Say," 12 July 2018 Buckeye Police Department alerted residents that its main phone line wasn't working due to the outage, and city buildings were also without power, according to Buckeye fire Capt. — Arizona Republic, azcentral, "Thousands without power in Buckeye on Monday after monsoon activity," 9 July 2018 At the site of a residential fire where a body was found, Bella alerted investigators to the presence of fuel in a master bedroom. — Grant Suneson And John Harrington, USA TODAY, "The 25 most heroic dogs in America," 5 July 2018 After one of the boys did not return from soccer practice, his mother alerted the authorities, prompting the search effort. — Eli Meixler, Time, "Thai Divers Continue the Search For 12 Boys and Their Coach Trapped in a Flooded Cave. Here’s What to Know," 26 June 2018 The emails contained a hidden image that alerted the attackers in real time when targets viewed the messages. — Dan Goodin, Ars Technica, "Iranian phishers bypass 2fa protections offered by Yahoo Mail and Gmail," 13 Dec. 2018 The intrusion was detected in April by an NRCC vendor, who alerted the committee and its cybersecurity contractor. — Casey Newton, The Verge, "Google’s appearance before Congress will mark a turning point for its CEO," 5 Dec. 2018

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.