alert
1 of 3adjective
ə-ˈlərt 
1
a
: 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
alertly adverb
alertness noun
alert
2 of 3noun
1
: a state of careful watching and readiness especially for danger or opportunity
on 24-hour alert
2
a
: 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
Ann Schrader3
: the period during which an alert is in effect
alert
3 of 3verb
alerted; alerting; alerts
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
Synonyms
Adjective
- Argus-eyed
- attentive
- awake
- observant
- open-eyed
- tenty [Scottish]
- tentie
- vigilant
- watchful
- wide-awake
Noun
- admonishment
- admonition
- alarm
- alarum
- caution
- forewarning
- heads-up
- notice
- warning
Verb
- advise
- caution
- forewarn
- wake
- warn
See all Synonyms & Antonyms 
Example Sentences
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 Harold Maass, The Week, 15 Aug. 2022 These entrepreneurs must remain very alert and make brilliant and quick business decisions. Josh Wilson, Forbes, 16 June 2022 Tesla states that drivers using Autopilot must remain alert and be prepared to take full control of the vehicle at a moment’s notice. Matt Mcfarland, CNN, 15 June 2022 Kansas Governor Laura Kelly urged residents to remain alert as severe weather moved across the state Friday night. Dennis Romero, NBC News, 30 Apr. 2022 But despite the good news, experts are pleading with Americans to remain alert, as the highly infectious delta variant continues to circulate. Arielle Mitropoulos, ABC News, 22 Oct. 2021 Caring adults who stay alert to digital dilemmas, set useful boundaries, and offer empathy, connection, and validation. WIRED, 22 Aug. 2022 The traveling public should stay alert and follow instructions from signage and flaggers. oregonlive, 8 Aug. 2022 During construction, the DOT said there may be overnight lane closures on Route 3 and motorists should slow down, keep a safe distance, stay alert, obey traffic signs, and use extreme caution in work zones. Stephen Underwood, Hartford Courant, 15 July 2022 Kathryn Prociv, NBC News, 7 Sep. 2022 The Stage 3 alert ended at 8 p.m. without major rotating outages. CBS News, 7 Sep. 2022 The city has already reported two deaths due to the rains and India’s Meteorological Department has issued a yellow alert for Bangalore, indicating further bad weather. Saritha Rai, Fortune, 7 Sep. 2022 Later in the day, police sent another alert saying Myles Sanderson – one of two brothers believed to have killed 10 people and wounded 18 in a series of stabbings – was not in the community. Nicole Fallert, USA TODAY, 7 Sep. 2022 The boil water alert covers about 1,500 homes and facilities across roughly 56 city blocks. Emily Opilo, Baltimore Sun, 6 Sep. 2022 Nearly half of that was slated for bullet-resistant shields for school police and $17.1 million was for districts to purchase panic-alert technology. Andrew Demillo, Chron, 6 Sep. 2022 Under the alert, people are encouraged to take transit, work remotely and limit driving, and to protect their health by avoiding outdoor activities during the hottest part of the day when air pollution levels are highest. Jessica Flores, San Francisco Chronicle, 6 Sep. 2022 Around noon, an alert was sent out reporting that the suspect vehicle had been seen by a driver on Arcola Avenue in Regina and told the public in Regina to shelter in place. Nouran Salahieh, CNN, 6 Sep. 2022 Xl Media, cleveland, 8 Sep. 2022 But after the victims wire that money, their banks alert them that the check from the scammers was bogus. Ron Hurtibise, Sun Sentinel, 8 Sep. 2022 This iPhone texting tip basically will alert you every time iOS attempts to autocorrect a word. Yoni Heisler, BGR, 6 Sep. 2022 Most connected charging stations can also alert EV charging smartphone apps if a station is available. Jordan Ramer, Forbes, 16 Aug. 2022 The funeral employee did not alert the family of Kyung Ja Kim until hours later, according to the suit. Michelle Watson, CNN, 27 July 2022 Those workers will alert police to threats, point people to homeless-service agencies and keep an eye on vulnerable people. Los Angeles Times, 5 July 2022 Any customer who feels worried or unsafe should absolutely alert the bartender and/or security staff. Amy Dickinson, oregonlive, 12 June 2022 Any customer who feels worried or unsafe should absolutely alert the bartender and/or security staff. Amy Dickinson, Detroit Free Press, 12 June 2022 See More
Adjective
The incident came as tensions were high at many federal facilities and the FBI was on alert following threats against the agency over its raid at former President Donald Trump's Florida home last week. Harold Maass, The Week, 15 Aug. 2022 These entrepreneurs must remain very alert and make brilliant and quick business decisions. Josh Wilson, Forbes, 16 June 2022 Tesla states that drivers using Autopilot must remain alert and be prepared to take full control of the vehicle at a moment’s notice. Matt Mcfarland, CNN, 15 June 2022 Kansas Governor Laura Kelly urged residents to remain alert as severe weather moved across the state Friday night. Dennis Romero, NBC News, 30 Apr. 2022 But despite the good news, experts are pleading with Americans to remain alert, as the highly infectious delta variant continues to circulate. Arielle Mitropoulos, ABC News, 22 Oct. 2021 Caring adults who stay alert to digital dilemmas, set useful boundaries, and offer empathy, connection, and validation. WIRED, 22 Aug. 2022 The traveling public should stay alert and follow instructions from signage and flaggers. oregonlive, 8 Aug. 2022 During construction, the DOT said there may be overnight lane closures on Route 3 and motorists should slow down, keep a safe distance, stay alert, obey traffic signs, and use extreme caution in work zones. Stephen Underwood, Hartford Courant, 15 July 2022 Noun
Wednesday will be the ninth consecutive day when a portion of the Golden State has been under a heat alert. Kathryn Prociv, NBC News, 7 Sep. 2022 The Stage 3 alert ended at 8 p.m. without major rotating outages. CBS News, 7 Sep. 2022 The city has already reported two deaths due to the rains and India’s Meteorological Department has issued a yellow alert for Bangalore, indicating further bad weather. Saritha Rai, Fortune, 7 Sep. 2022 Later in the day, police sent another alert saying Myles Sanderson – one of two brothers believed to have killed 10 people and wounded 18 in a series of stabbings – was not in the community. Nicole Fallert, USA TODAY, 7 Sep. 2022 The boil water alert covers about 1,500 homes and facilities across roughly 56 city blocks. Emily Opilo, Baltimore Sun, 6 Sep. 2022 Nearly half of that was slated for bullet-resistant shields for school police and $17.1 million was for districts to purchase panic-alert technology. Andrew Demillo, Chron, 6 Sep. 2022 Under the alert, people are encouraged to take transit, work remotely and limit driving, and to protect their health by avoiding outdoor activities during the hottest part of the day when air pollution levels are highest. Jessica Flores, San Francisco Chronicle, 6 Sep. 2022 Around noon, an alert was sent out reporting that the suspect vehicle had been seen by a driver on Arcola Avenue in Regina and told the public in Regina to shelter in place. Nouran Salahieh, CNN, 6 Sep. 2022 Verb
But a loss will alert Barstool to send you a free bet of equal value, up to $1,000. Xl Media, cleveland, 8 Sep. 2022 But after the victims wire that money, their banks alert them that the check from the scammers was bogus. Ron Hurtibise, Sun Sentinel, 8 Sep. 2022 This iPhone texting tip basically will alert you every time iOS attempts to autocorrect a word. Yoni Heisler, BGR, 6 Sep. 2022 Most connected charging stations can also alert EV charging smartphone apps if a station is available. Jordan Ramer, Forbes, 16 Aug. 2022 The funeral employee did not alert the family of Kyung Ja Kim until hours later, according to the suit. Michelle Watson, CNN, 27 July 2022 Those workers will alert police to threats, point people to homeless-service agencies and keep an eye on vulnerable people. Los Angeles Times, 5 July 2022 Any customer who feels worried or unsafe should absolutely alert the bartender and/or security staff. Amy Dickinson, oregonlive, 12 June 2022 Any customer who feels worried or unsafe should absolutely alert the bartender and/or security staff. Amy Dickinson, Detroit Free Press, 12 June 2022 See More Word History
Etymology
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
First Known Use
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
Phrases Containing alert
Kids Definition
alert 1 of 3
adjective
ə-ˈlərt
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
Lois Lowry, The Giver2
: quick to understand and act
An alert reader noticed the error in grammar.
alert
2 of 3noun
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.
alert
3 of 3verb
alerted; alerting
: to make aware of a need to get ready or take action : warn
The siren alerted us that a tornado was approaching.
alert 1 of 3
noun
1
as in warning
the act or an instance of telling beforehand of danger or risk the white flash of the doe's raised tail, giving the "danger" alert to her fawns Synonyms & Similar Words
Relevance
- warning
- alarm
- forewarning
- caution
- advice
- admonition
- informing
- notice
- suggestion
- admonishment
- recommendation
- heads-up
- alarum
- prediction
- notification
- predicting
- notifying
- forecasting
- announcement
- apprising
- guidance
- prophecy
- prophesy
- premonition
- presaging
- tip
- declaration
- foretelling
- prophesying
- tip-off
- augury
- prognosticating
- counsel
- auguring
2
as in watchfulness
the state of being constantly attentive and responsive to signs of opportunity, activity, or danger the doctor told the patient to be on the alert for any signs of infection Synonyms & Similar Words
- watchfulness
- watch
- alertness
- vigilance
- attentiveness
- red alert
- awareness
- sensitivity
- mindfulness
- consciousness
- qui vive
- receptivity
- readiness
- receptiveness
- cautiousness
- aliveness
- wariness
- preparation
- carefulness
- care
- chariness
- heedfulness
Antonyms & Near Antonyms
- daze
- daydreaming
- distraction
- preoccupation
- abstraction
- absorption
- unawareness
- obliviousness
- absentmindedness
- unconsciousness
- inattention
- engrossment
- inattentiveness
- carelessness
- heedlessness
- inobservance
- unwariness
alert
2 of 3verb
as in to warn
to give notice to beforehand especially of danger or risk alerted us to the possibility that the roads would be flooded and we might have to take a detour Synonyms & Similar Words
- warn
- advise
- inform
- caution
- wake
- forewarn
- notify
- forecast
- apprise
- predict
- admonish
- presage
- harbinger
- prophesy
- prognosticate
- foretell
- augur
- forebode
- bode
- foreshadow
- tip (off)
- portend
- foretoken
- forbode
Antonyms & Near Antonyms
- risk
- imperil
alert
3 of 3adjective
1
as in awake
paying close attention usually for the purpose of anticipating approaching danger or opportunity she needed to stay alert throughout the train ride so as not to miss her stop Synonyms & Similar Words
- awake
- vigilant
- watchful
- aware
- attentive
- cautious
- observant
- careful
- alive
- wary
- sensitive
- regardful
- conscious
- prepared
- on guard
- wide-awake
- keen
- open-eyed
- mindful
- cognizant
- on tiptoe
- tentie
- on the alert
- Argus-eyed
- wakeful
- tenty
- heedful
- observing
- hyperalert
- hypervigilant
- ready
- on the qui vive
- on the ball
- on one's toes
- sleepless
- sharp-eyed
- chary
- sharp
Antonyms & Near Antonyms
- oblivious
- distracted
- unaware
- absent
- preoccupied
- asleep
- unconscious
- dazed
- sleeping
- dreaming
- absorbed
- unwitting
- engrossed
- dreamy
- inattentive
- careless
- abstracted
- unknowing
- unmindful
- insensible
- absentminded
- unwary
- heedless
- unprepared
- daydreaming
- unthinking
- faraway
- unready
- unheeding
2
as in cautious
having or showing a close attentiveness to avoiding danger or trouble warned us to be alert to the presence of pickpockets on the crowded bus Synonyms & Similar Words
- cautious
- wary
- careful
- guarded
- considerate
- heedful
- circumspect
- vigilant
- watchful
- safe
- attentive
- chary
- awake
- conservative
- thoughtful
- gingerly
- observant
- advertent
- regardful
- foresighted
- deliberate
- cagey
- provident
- slow
- calculating
- hypercautious
- shrewd
- canny
- forethoughtful
- foresightful
- cagy
- ultracautious
- ultracareful
Antonyms & Near Antonyms
- careless
- unmindful
- unsafe
- unwary
- heedless
- bold
- rash
- inattentive
- reckless
- unguarded
- regardless
- asleep
- impetuous
- venturesome
- incautious
- negligent
- lax
- thoughtless
- brash
- forgetful
- inconsiderate
- remiss
- inadvertent
- neglectful
- indiscreet
- imprudent
- unintentional
- injudicious
- unplanned
- absentminded
3
as in intelligent
having or showing quickness of mind an alert and well-trained sheep dog who can handle difficult situations Synonyms & Similar Words
- intelligent
- smart
- quick
- clever
- fast
- keen
- sharp
- brilliant
- bright
- educated
- exceptional
- wise
- informed
- wise
- nimble
- skilled
- brainy
- quick-witted
- schooled
- learned
- astute
- resourceful
- literate
- trained
- perceptive
- savvy
- discerning
- acute
- knowing
- sensible
- cunning
- sharp-witted
- hyperintelligent
- supersmart
- ultrasmart
- apt
- perspicacious
- sound
- knowledgeable
- insightful
- prudent
- sagacious
- creative
- cerebral
- sane
- percipient
- ingenious
- erudite
- logical
- reasonable
- judicious
- rational
- highbrow
- heady
- scholarly
- inventive
- wily
- sage
- sapient
- genial
- well-read
- shrewd
- crafty
- foxy
- sapient
Antonyms & Near Antonyms
- dumb
- stupid
- slow
- dim
- dense
- simple
- soft
- dopey
- dull
- mindless
- obtuse
- pinheaded
- opaque
- unintelligent
- lamebrain
- fatuous
- witless
- vacuous
- doltish
- boneheaded
- foolish
- softheaded
- brainless
- thick
- dunderheaded
- bubbleheaded
- lamebrained
- unbrilliant
- senseless
- uninformed
- silly
- chuckleheaded
- thickheaded
- knuckleheaded
- ignorant
- dopy
- brain-dead
- feebleminded
- gormless
- unsmart
- simpleminded
- dorky
- idiotic
- dim-witted
- imbecile
- moronic
- uneducated
- airheaded
- idiotical
- unthinking
- mad
- slow-witted
- empty-headed
- illiterate
- lunkheaded
- half-witted
- imbecilic
- birdbrained
- weak-minded
- thick-witted
- fool
- untaught
- crazy
- unwise
- insane
- nutty
- absurd
- whacky
- boobish
- zany
- cuckoo
- wacky
- loony
- lowbrow
- daft
- preposterous
- lunatic
- dippy
- sappy
- nonintellectual
- unintellectual
- kooky
- harebrained
- daffy
- balmy
- nonsensical
- screwball
- asinine
- unacademic
- looney
- dotty
- crackpot
- cockeyed
- half-baked
- featherheaded
- kookie
- tomfool
- half-baked
4
as in quick
having or showing the ability to respond without delay or hesitation an alert force of commandos, ready to go on a mission at a moment's notice Synonyms & Similar Words
- quick
- prompt
- immediate
- responsive
- ready
- swift
- willing
- keen
- receptive
- rapid
- brisk
- expeditious
- eager
- clever
- smart
- summary
- alacritous
- instant
- fast
- sharp
- instantaneous
- rattling
- breathless
- lightning
- fleet
- speedy
- apt
- snappy
- whirlwind
- quick-witted
- breakneck
- fleet-footed
- rapid-fire
- sharp-witted
- hit-and-run
- ready-witted
Antonyms & Near Antonyms
- unresponsive
- creeping
- slow
- lazy
- crawling
- lagging
- sluggish
- tardy
- dragging
- inactive
- unhurried
- laggard
- poking
- slothful
- idle
- dormant
- dilatory
- loggy
- pokey
- leisurely
- inert
- dillydallying
- logy
- lazyish
- poky
- dawdling
- dallying
- slowish
Synonym Chooser
Some common synonyms of alert are vigilant, watchful, and wide-awake. While all these words mean "being on the lookout especially for danger or opportunity," alert stresses readiness or promptness in meeting danger or in seizing opportunity.
alert traders anticipated the stock market's slide
The synonyms vigilant and alert are sometimes interchangeable, but vigilant suggests intense, unremitting, wary watchfulness.
eternally vigilant in the safeguarding of democracy
In some situations, the words watchful and alert are roughly equivalent. However, watchful is the least explicit term.
the watchful eye of the department supervisor
The words wide-awake and alert can be used in similar contexts, but wide-awake applies to watchfulness for opportunities and developments more often than dangers.
wide-awake companies latched onto the new technology