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

Ollongren also warned of the deteriorating security situation in the Middle East and the war’s adverse effects on human rights in Iran and the broader region. —Morgan Chalfant, semafor.com, 9 Mar. 2026

The Middle East war, which has shown little sign of easing, may continue to push China’s producer prices higher at least through March, said Zhang, warning that a prolonged conflict risks tipping the global economy into stagflation. —Anniek Bao, CNBC, 9 Mar. 2026

That could raise new credit risks for emerging markets, warned Fitch Ratings, as higher oil prices bloat subsidy and import bills and disrupt remittances, tourism and investment flows. —Claire Jiao, Bloomberg, 9 Mar. 2026

Emails obtained by Fox 5 DC and WJLA-TV show that the Fairfax County Police Department had warned Descano’s office multiple times about Jalloh in the months leading up to Minter’s murder. —Mia Cathell, The Washington Examiner, 9 Mar. 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
• mourn
• porn
• scorn
• shorn
• sworn
• thorn
• torn

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