English dictionary

alert Meaning & Definition

Q: What is the past tense of alert?

The past tense of alert is alerted. The present participle is alerting.

ə-ˈlərt

What Does Alert Mean?

Alert is used as an adjective meaning watchful and prompt to meet danger or emergency. It can also mean quick to perceive and act. As a noun, it means a state of careful watching and readiness especially for danger or opportunity. As a verb, it means to call (someone) to a state of readiness.

Alert in Brief

Part of speech	adjective, noun, verb
Pronunciation	/ə-ˈlərt/
Syllables	2
Synonyms	conscious, intelligent and vigilant
Antonyms	unalert, absentmindedness and abstraction
Plural	alerts
Comparative / superlative	more alert, most alert
Verb forms	alerts, alerting, alerted
Adverb	alertly
First known use	1868

Alert Definition (Adjective)

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

Alert as a Noun

a state of careful watching and readiness especially for danger or opportunity
on 24-hour alert
an alarm or other signal of danger
traffic alerts / They sounded the alert.
an urgent notice
… an alert to parents … about new immunization requirements.
the period during which an alert is in effect

Alert as a Verb

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

Antonyms of Alert

unalert absentmindedness abstraction daydreaming daze distraction absorption engrossment obliviousness preoccupation unawareness unconsciousness carelessness heedlessness inattention inattentiveness inobservance unwariness imperil risk asleep absent absentminded absorbed abstracted dazed distracted dreaming dreamy engrossed faraway insensible oblivious preoccupied sleeping unaware unconscious unknowing unwitting careless heedless inattentive unheeding unmindful unthinking unwary unprepared unready incautious unguarded unsafe bold brash impetuous rash reckless venturesome regardless inconsiderate thoughtless lax neglectful negligent remiss imprudent indiscreet injudicious forgetful inadvertent unintentional unplanned airheaded birdbrained boneheaded brain-dead brainless bubbleheaded chuckleheaded dense dim dim-witted doltish dopey dorky dull dumb dunderheaded empty-headed fatuous gormless half-witted knuckleheaded lamebrain lunkheaded mindless obtuse opaque pinheaded senseless simple slow slow-witted soft softheaded stupid thick thickheaded thick-witted unbrilliant unintelligent unsmart vacuous weak-minded witless feebleminded simpleminded boobish foolish half-baked idiotic imbecile moronic silly ignorant illiterate lowbrow nonintellectual unacademic uneducated uninformed unintellectual untaught absurd asinine balmy cockeyed crackpot crazy cuckoo daffy daft dippy dotty featherheaded fool harebrained insane kooky loony mad nonsensical nutty preposterous sappy screwball tomfool unwise wacky zany unresponsive crawling creeping dallying dawdling dilatory dillydallying dragging laggard lagging lazy lazyish leisurely logy poking poky slothful slowish sluggish tardy unhurried dormant idle inactive inert

Alert in a Sentence

an airborne alert; ground alert

an alert guard

trying to stay alert to possible problems

mentally alert

elicited an alert response

on 24-hour alert

traffic alerts

They sounded the alert.

… an alert to parents … about new immunization requirements.

alerted the school board of a possible teachers' strike

alert the authorities

alerted the public to the dangers of pesticides

the white flash of the doe's raised tail, giving the danger alert to her fawns

the doctor told the patient to be on the alert for any signs of infection

alerted us to the possibility that the roads would be flooded and we might have to take a detour

she needed to stay alert throughout the train ride so as not to miss her stop

warned us to be alert to the presence of pickpockets on the crowded bus

an alert and well-trained sheep dog who can handle difficult situations

an alert force of commandos, ready to go on a mission at a moment's notice

an alert guard / trying to stay alert to possible problems

traffic alerts / They sounded the alert.

alerted the school board of a possible teachers' strike / alert the authorities

Word Forms & Grammar

alert·ly adverb

alert·ness noun

alert

alerter

alertest

alertly

alertness

alertnesses

alerts

alert·ed

alert·ing

alerted

alerting

alert (comparative more alert, superlative most alert)

alert (plural alerts)

alert (third-person singular simple present alerts, present participle alerting, simple past and past participle alerted)

Words That Rhyme With Alert

assert inert overt spurt hurt convert subvert pervert avert flirt desert blurt exert skirt revert disconcert squirt divert turret vert invert introvert girt concert dirt undershirt reassert chert nightshirt extrovert

Origin of Alert

Origin 1: 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) erect:1

Origin 2: noun derivative of alert:1 (or borrowed from French alerte, derivative of alerte, adjective)

Origin 3: verbal derivative of alert:1 or alert:2

Origin 4: From French alerte (“alert”), from the phrase à l'erte (“on the watch”), from Italian all'erta (“to the height”), from erta (“lookout, tower”).[1]

Origin 5: Formed within English by conversion, from alert (adjective). Compare French alerter.[2]

First Known Use

1618

1801

circa 1868

How to Pronounce Alert

Alert is pronounced /ə-ˈlərt/ and has 2 syllables, with the main stress on the second syllable (lərt).

Alert: Your Questions Answered

Is alert an adjective or a noun?

Alert is mainly used as an adjective, but it can also be used as a noun and a verb.

What is another word for alert?

You can replace alert with words such as conscious, intelligent and vigilant. See the full list of alert synonyms and antonyms.

What is the opposite of alert?

The opposite of alert can be expressed with words like unalert, absentmindedness, abstraction and daydreaming.