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

• advise
• alert
• caution
• forewarn
• wake

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

Dangerous fire conditions are expected to return next week, the National Weather Service warned. —Minyvonne Burke, NBC News, 17 Jan. 2025

Bolden, who’d warned about lax security practices around President John F. Kennedy, was charged in 1964 with attempting to sell a copy of a Secret Service file to a ring of counterfeiters. —Steve Rosenberg, Chicago Tribune, 16 Jan. 2025

Live Live updates: ‘Particularly dangerous situation’ winds warning returns Wednesday morning But concern is mounting as the education of thousands of children is once again in disarray. —Teresa Watanabe, Los Angeles Times, 16 Jan. 2025

Still, one strategist warned the market’s recent fickle nature should keep investors on their toes. —Danielle Chemtob, Forbes, 16 Jan. 2025

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

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