va·​por | \ ˈvā-pər How to pronounce vapor (audio) \

Definition of vapor

 (Entry 1 of 2)

1 : diffused matter (such as smoke or fog) suspended floating in the air and impairing its transparency
2a : a substance in the gaseous state as distinguished from the liquid or solid state
b : a substance (such as gasoline, alcohol, mercury, or benzoin) vaporized for industrial, therapeutic, or military uses also : a mixture (such as the explosive mixture in an internal combustion engine) of such a vapor with air
3a : something unsubstantial or transitory : phantasm
b : a foolish or fanciful idea

4 vapors plural

a archaic : exhalations of bodily organs (such as the stomach) held to affect the physical or mental condition
b : a depressed or hysterical nervous condition


vapored; vaporing\ ˈvā-​p(ə-​)riŋ How to pronounce vaporing (audio) \

Definition of vapor (Entry 2 of 2)

intransitive verb

1a : to rise or pass off in vapor
b : to emit vapor
2 : to indulge in bragging, blustering, or idle talk

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Other Words from vapor


vaporer \ -​pər-​ər How to pronounce vaporer (audio) \ noun

Synonyms for vapor

Synonyms: Verb

blow, boast, brag, bull [slang], crow, gasconade, swagger, vaunt

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Did You Know?


Speakers of the English language, mindful of the lightness and unsubstantiality of floating air and gas, have put several airy words to good use over the years to describe the act of talking idly or boastfully. The earliest such word is blow (as in "he kept blowing about his new job"), which drifted into English sometime about 1400. Vapor wafted into the language in the 1620s, and a little over 200 years later windbags, later also known as gasbags, not only blew and vapored but also gassed about anything they could.

Examples of vapor in a Sentence


a faded Southern belle tiresomely vaporing about all the handsome beaux she had in her long-ago youth

Recent Examples on the Web: Noun

Recent research shows that e-cigarettes are a gateway to regular smoking for adolescents, while other studies show that the 'e-juice' that produces vapor may contain harmful, even cancer-causing chemicals. Sandee Lamotte, CNN, "FDA chief: Opioids are "biggest crisis facing the FDA""," 5 Apr. 2018 Regions that start out white are colder and become the sites where those sublimated vapors condense. Carolyn Porco, Scientific American, "Cassini at Saturn: A Retrospective," 1 Oct. 2017 Plus, when the sun beats down on the damp door, any moisture under the paint turns into vapor and forces its way through the topcoat. Roy Berendsohn, Popular Mechanics, "Why Won't My Galvanized Steel Door Hold Paint?," 13 Nov. 2016 Those same chemicals carry over into the vapor that people inhale, the new study says. Rachel Becker, The Verge, "Vape flavors can make nasty new chemicals in your e-liquid," 18 Oct. 2018 This type of pollution is generally caused by motor vehicle exhaust, industrial emissions, gasoline vapors, and chemical solvents, NOAA says. Korin Miller, SELF, "How to Stay Safe When Your City’s Air Quality Is Dangerous," 21 Aug. 2018 But that's not enough to overcome the extremely low pressures of the Martian atmosphere, which would cause any ice to sublimate off into vapor instead of melting. John Timmer, Ars Technica, "Possible lake spotted under a polar ice cap—on Mars," 25 July 2018 The researchers exposed cultured human bronchial cells to diluted cinnamon e-liquids and to e-liquid aerosol, or vapor, from an e-cigarette device purchased at a local vape shop in Chapel Hill. Roni Caryn Rabin, New York Times, "Cinnamon May Be Safe in Foods, but Is It Safe in E-Cigarettes?," 1 June 2018 Evaporative: For this type, a fan draws air through a wet wick or filter and the vapor is released into the air. Rachel Rothman, Good Housekeeping, "The Best Humidifiers to Buy This Winter," 20 Dec. 2018

Recent Examples on the Web: Verb

But whole body cryotherapy exposes the body for a couple of minutes to vapor that has been supercooled to somewhere between minus 200 and minus 300 degrees Fahrenheit. Aaron E. Carroll, New York Times, "Cold Therapy? Maybe Better Save Your Money," 2 Jan. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'vapor.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of vapor


14th century, in the meaning defined at sense 1


15th century, in the meaning defined at sense 1a

History and Etymology for vapor


Middle English vapour, borrowed from Anglo-French & Latin; Anglo-French vapor, vapour, borrowed from Latin vapor, earlier vapōs "exhalation, steam, warmth," perhaps akin to Lithuanian kvãpas "smell, scent"

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Statistics for vapor

Last Updated

8 Mar 2019

Look-up Popularity

Time Traveler for vapor

The first known use of vapor was in the 14th century

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More Definitions for vapor



English Language Learners Definition of vapor

: a substance that is in the form of a gas or that consists of very small drops or particles mixed with the air


va·​por | \ ˈvā-pər How to pronounce vapor (audio) \

Kids Definition of vapor

1 : fine bits (as of fog or smoke) floating in the air and clouding it
2 : a substance in the form of a gas water vapor


variants: or chiefly British vapour \ ˈvā-​pər How to pronounce vapour (audio) \

Medical Definition of vapor

1a : a substance in the gaseous state as distinguished from the liquid or solid state
b : a substance (as alcohol or benzoin) vaporized for industrial, therapeutic, or military uses

2 vapors or chiefly British vapours plural

a : exhalations of bodily organs (as the stomach) formerly held to affect the physical or mental condition
b : a depressed or hysterical nervous condition

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More from Merriam-Webster on vapor

Rhyming Dictionary: Words that rhyme with vapor

Thesaurus: All synonyms and antonyms for vapor

Spanish Central: Translation of vapor

Nglish: Translation of vapor for Spanish Speakers

Britannica English: Translation of vapor for Arabic Speakers

Comments on vapor

What made you want to look up vapor? Please tell us where you read or heard it (including the quote, if possible).


to corrupt or become corrupted

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