warn

verb

ˈwȯrn 

warned; warning; warns

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

Synonyms of warn

• alert
• advise

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 on the Web

No deaths had been confirmed as of Friday afternoon, although emergency officials warned that assessments were continuing and communications with some affected communities remained difficult. — Antonio María Delgado, Miami Herald, 9 Oct. 2026

The district may need state intervention or an emergency loan to keep operating, the agency warned. — Chaewon Chung, Sacbee.com, 9 Oct. 2026

When Lovat basically laughs at him for throwing everything away for a woman, Brian drops a sassy line about still having his conscience when all this is through and then rides off with Ellen to warn Dougal what’s coming. — Maggie Fremont, Vulture, 9 Oct. 2026

But the majority of the country’s stormwater infrastructure was not built for heavier bouts of rain brought by a warming climate — and now experts are warning the ongoing super El Niño will further expose those risks across the nation. — Erin Douglas, Washington Post, 9 Oct. 2026

Word History

Etymology

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 ware entry 1

First Known Use

before the 12th century, in the meaning defined at transitive sense 1a

Phrases Containing warn

• I have to warn you
• pre-warn
• warn off

Rhymes for warn

• borne
• bourn
• bourne
• corn
• morn
• morne
• mourn
• porn
• scorn
• shorn
• sworn
• thorn

Kids Definition

warn

verb

ˈwȯ(ə)rn 

1

a

: to give notice to beforehand especially of danger or evil

b

: to give advice to : counsel

2

: to order to go or stay away

warned us off their land

warner noun