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

According to authorities, store staff had been warned that the same suspects had allegedly attempted a similar scheme at a Costco location in Enfield, roughly a 30-minute drive north. — Bonny Chu, FOXNews.com, 2 July 2026

Wisconsin girl began rabies treatment after bat bite The report comes as public health officials continue to warn about rabies risks following a recent case in Wisconsin, where a 6-year-old girl received preventive treatment after a bat bite. — Anthony Thompson, USA Today, 2 July 2026

The Justice Department portrays the group as antifa militants, while defense lawyers and civil liberties advocates warn the case could reshape how protests and free speech rights are prosecuted nationwide. — Jamie Stengle, Los Angeles Times, 1 July 2026

The mistake, the one his jazz teacher warned against, is walking into the encounter trying to win it. — Afdhel Aziz, Forbes.com, 1 July 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