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

Despite diesel prices hitting a record high this week and home heating oil up 50% in just three months, the state’s fuel distributors warn the problems are far from over. — Keith M. Phaneuf, Hartford Courant, 26 Sep. 2026

However, because the Food and Drug Administration has warned about a potential for birth abnormalities, it is not recommended for women who are pregnant or who want to get pregnant. — Lindsey Bever, Washington Post, 26 Sep. 2026

Gartner’s March 2026 survey of 204 finance leaders found 45% of finance AI investment leaning toward productivity against only 20% toward decision quality, and warned of a widening gap between what finance reports and what boards see. — Pankaj Prasoon, Forbes.com, 25 Sep. 2026

Officials floated a 51% threshold last year, drawing pushback from the Chamber of Mines, which warned against importing other countries’ models. — Yinka Adegoke, semafor.com, 25 Sep. 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