Showing results for warn. Search instead for to warn.

Synonyms

warn

American

[wawrn] / wɔrn /

verb (used with object)

to give notice, advice, or intimation to (a person, group, etc.) of danger, impending evil, possible harm, or anything else unfavorable.

They warned him of a plot against him. She was warned that her life was in danger.

Synonyms:

forewarn
to urge or advise to be careful; caution.

to warn a careless driver.
to admonish or exhort, as to action or conduct.

She warned her employees to be on time.
to notify, advise, or inform.

to warn a person of an intended visit.
to give notice to (a person, group, etc.) to go, keep at a distance, etc. (often followed by away, off, etc.).

A sign warns trespassers off the grounds. A marker warned boats away from the dock.
to give authoritative or formal notice to (someone); order; summon.

to warn a person to appear in court.

verb (used without object)

to give a warning; caution.

to warn of further disasters.

warn British

/ wɔːn /

verb

to notify or make (someone) aware of danger, harm, etc
(tr; often takes a negative and an infinitive) to advise or admonish (someone) as to action, conduct, etc

I warn you not to do that again
(takes a clause as object or an infinitive) to inform (someone) in advance

he warned them that he would arrive late
(tr; usually foll by away, off, etc) to give notice to go away, be off, etc

he warned the trespassers off his ground

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Synonym Usage

Warn, caution, admonish imply attempting to prevent another from running into danger or getting into unpleasant or undesirable circumstances. To warn is to speak plainly and usually in strong terms: to warn him about danger and possible penalties. To caution is to advise about necessary precautions, to put one on one's guard about possibly harmful circumstances or conditions, thus emphasizing avoidance of undesirable consequences: to caution him against driving in such weather. Admonish suggests giving earnest, authoritative advice with only tacit references to danger or penalty: to admonish a person for neglecting his duties.

Other Word Forms

Derived Forms

Inflected Forms

Participles

Conjugated Forms

Present

Past

Future

Etymology

Origin of warn

First recorded before 1000; Middle English warnen, Old English warnian; cognate with German warnen; Cf. ware ²

Explanation

When you warn someone, you advise them to be careful or tell them about a problem or danger. If you perform a dangerous stunt, you should probably warn your audience, "Don't try this at home." Many traffic signs are meant to warn drivers about hazards, like bridges that get slippery in the rain or bumps in the road. And the purpose of a dog's growl is to warn another dog (or human) that it's stressed or fearful. A warning is a helpful message, no matter what form it comes in, and to warn is to send this message. The Old English root is warnian, "give notice of impending danger."

Keep Reading on Vocabulary.com

Vocabulary lists containing warn

"The Secret Water"

Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!

"The Black Ferris" by Ray Bradbury

Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!

Tasting the Sky

Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

warn warns warned warning

The referee stopped the match during his narrow win against Nathan Aspinall in the last eight on Saturday to warn the hostile crowd about its behaviour, before play resumed.

From BBC ● Sep. 20, 2026

Despite publicising her experience to warn other traders and reporting the scam, she said she did not know how they could be stopped.

From BBC ● Sep. 18, 2026

Her family sued a distributor of Alani Nu energy drinks, alleging their marketing targeted minors and the cans failed to adequately warn of their caffeine content.

From The Wall Street Journal ● Sep. 15, 2026

California lawmakers call for criminal penalties and emergency legislation as tech leaders warn of existential risks from rogue AI.

From Los Angeles Times ● Sep. 14, 2026

He figured there was something wrong with the new plumbing connections, maybe a gas leak, and he ran to the top of the street to warn people away in case of an explosion.

From "The Best School Year Ever" by Barbara Robinson

Yet that same database warns against exactly this kind of comparison, because disasters have been far better recorded since 2000.

From The Wall Street Journal ● Sep. 17, 2026

The ChatGPT developer warns that the AI industry won’t be able to scale at maximum speed much longer.

From Barron's ● Sep. 17, 2026

It warns that safeguarding election integrity is a prerequisite for any candidate’s viability, regardless of message.

From Los Angeles Times ● Sep. 13, 2026

The report warns that upcoming Fed meetings could catalyze rate volatility if the tightening that the markets demand isn’t forthcoming.

From MarketWatch ● Sep. 10, 2026

“You better eat some more steak before your brothers finish it all,” Mom warns me.

From "Starfish" by Akemi Dawn Bowman

The letter said automotive suppliers already possessed many of the capabilities needed to support aircraft, defence equipment and military vehicles, but warned firms needed help to make the transition.

From BBC ● Sep. 20, 2026

In June he revealed a state budget measure that capped how much in tax credits a business can claim each year, a limit industry groups warned would undercut the expanded program.

From Los Angeles Times ● Sep. 19, 2026

Amodei, who had warned Congress about the risk of bad actors using open-sourced AI, issued a letter pushing back against any suggestion that he wanted to ban open models.

From The Wall Street Journal ● Sep. 19, 2026

Meanwhile, oil stockpiles continue dropping toward record lows, as highlighted by a new analysis from the S&P Global Energy Fuels and Refining team, which warned “winter is coming for diesel markets.”

From Salon ● Sep. 19, 2026

With the election just weeks away, Senator Kennedy, the Democratic nominee for president, warned that America was losing the Cold War.

From "Fallout: Spies, Superbombs, and the Ultimate Cold War Showdown" by Steve Sheinkin

Charities are warning that thousands of low income families are missing out on money they are eligible to claim to buy fresh fruit, vegetables, and milk.

From BBC ● Sep. 20, 2026

Researchers have identified early molecular warning signs of inflammatory bowel disease that may appear before symptoms and remain active even when patients seem to be doing well.

From Science Daily ● Sep. 20, 2026

In the sky, reporters and pilots keep an eye out for one another, warning when one is drifting too close to another or if there is something else to keep an eye on.

From Los Angeles Times ● Sep. 19, 2026

“The better we do on GPT-X, the more worried genre fiction authors will become about us substituting for them on Amazon,” Jack Clark, OpenAI’s former policy director, said in an internal warning in 2020.

From The Wall Street Journal ● Sep. 19, 2026

Her face as she turned to the horizon had the kind of look that ought to come with a warning sign: Stand clear: danger.

From "Impossible Creatures" by Katherine Rundell

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023