warn

verb \ ˈwȯrn \

Updated on: 13 Apr 2018

Definition of warn

transitive verb

1 a : to give notice to beforehand especially of danger or evil

b : to give admonishing advice to : counsel

c : to call to one's attention : inform

2 : to order to go or stay away —often used with off

intransitive verb

: to give a warning

—

warner

noun

See warn defined for English-language learners

See warn defined for kids

Examples of warn in a Sentence

I had been warned about the difficulties of the job.
She warned me that the stove was still hot.
“This won't be easy,” he warned.
Nobody warned me about the dangers.
I warned him to be careful, but he didn't listen to me.
She warned us not to go too close to the fire.

Recent Examples of warn from the Web

On the other hand, academic writers, such as Brendan Nyhan, warn that the political power of targeted online ads and Russian bots are widely overblown.

— sander van der linden, Scientific American, "Psychological Weapons of Mass Persuasion," 10 Apr. 2018
DeJohn warned residents that Mayor Anthony DiCicco would put in the city's general fund the $5.2 million that would result from a successful passage of a .50-percent income tax increase in November.

— jeff piorkowski/special to cleveland.com, cleveland.com, "Mayfield Heights Mayor DiCicco, Councilman DeJohn disagree on where the money should go," 10 Apr. 2018
Most of the cases in the outbreak involved synthetic marijuana purchased from Chicago-area convenience stores, dealers, or friends, but officials warn the contaminated products could be in counties across the state or beyond.

— CBS News, "3 deaths tied to excessive bleeding from synthetic marijuana, possibly tainted with rat poison," 10 Apr. 2018
The Memorial Sloan Kettering Cancer Center warns that ashwagandha, an ayurvedic herb used in Moon Dusts and a Hum formula, has a variety of potential side effects, possibly including miscarriage.

— cheryl wischhover, Vox, "Vitamins for your hair, nails, and skin are everywhere on Instagram. Don’t fall for them.," 9 Apr. 2018
Forty years ago, when the first at-home pregnancy tests became available, some physicians warned against their use.

— anne wojcicki, STAT, "Consumers don’t need experts to interpret 23andMe genetic risk reports," 9 Apr. 2018
Then without warning in 2008, Katherine’s life changed forever.

— alexis reliford, Redbook, "After a Stroke at 26, a Mom Turned Her Recovery Into a Message of Hope," 9 Apr. 2018
Paige Schwahn/USA Today Network Wochit Coconino County officials warned residents east of Flagstaff to prepare for a possible evacuation Sunday afternoon due to a fast-moving fire.

— bree burkitt, azcentral, "Coconino officials: Fast-moving fire could force evacuation near Flagstaff," 8 Apr. 2018
Doonan, a wildlife biologist for 24 years, warned against handling bats because of the risk of rabies.

— stephen hudak, OrlandoSentinel.com, "Bats in your attic? Boot them out now before you can't when bat maternity season hits," 7 Apr. 2018

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

Origin and Etymology of warn

Middle English warnen, going back to Old English wearnian, warnian "to be on one's guard, make aware, put on one's guard," going back to West Germanic *warnōjan- (whence Middle Dutch waernen "to provide with, give notice of a danger," Old High German warnōn), probably causative derivative of Germanic *wara- "cognizant, watchful" — more at ¹ware

NEW! Time Traveler

First Known Use: before 12th century

in the meaning defined at transitive sense 1a

See Words from the same year