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
warner noun

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
And now Google warns that Chrome is under attack, issuing an emergency update and a recommendation to upgrade all desktop browsers immediately. Zak Doffman, Forbes.com, 18 Sep. 2025 National Hurricane Center The National Oceanic and Atmospheric Administration previously warned of a heightened risk for major hurricanes in the Atlantic due to record-breaking sea surface temperatures and the ongoing transition from El Niño to La Niña conditions. Theo Burman, MSNBC Newsweek, 18 Sep. 2025 With Kennedy at the helm of HHS, major medical organizations have expressed extreme alarm about restrictions to COVID-19 vaccines that have already taken place and warned of potential further restrictions to routine childhood vaccines. Sony Salzman, ABC News, 17 Sep. 2025 In a December 2023 Slate editorial, security researcher Bruce Schneier warned that AI models could enable unprecedented mass spying by automating the analysis and summarization of vast conversation datasets. Benj Edwards, ArsTechnica, 17 Sep. 2025 See All Example Sentences for warn

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

Time Traveler
The first known use of warn was before the 12th century

Browse Nearby Words

Cite this Entry

“Warn.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/warn. Accessed 18 Sep. 2025.

Kids Definition

warn

verb
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

More from Merriam-Webster on warn

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!