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

Inside is a heating element that’s activated by suction—when someone inhales, the mixture is heated and a white cloud of aromatherapy vapor emerges. Kathryn Tuggle, Good Housekeeping, "The Rise Of The "Personal Diffuser" Stick—Is Essential Oil Vaping Safe?," 19 Sep. 2017 Then, a move had to be made through the claustrophobic sewers, measuring less than a meter-wide toward the bank that could at any time get filled with water or noxious vapors. Raf Casert, The Seattle Times, "A tunnel, a hole in the floor: Belgium ponders bank heist," 4 Feb. 2019 Water, present as a vapor or even as a liquid in a tire, causes more of a pressure change with temperature swings than dry air does. Ezra Dyer, Popular Mechanics, "Should You Really Put Nitrogen in Your Car Tires?," 19 Dec. 2018 The device produces vapor in a variety of fruit and mint flavors, and is so well-known that students have turned Juul into a verb, Sward added. Dennis Thompson,, "E-cigarettes disguised as USB drives could be getting more teens hooked on nicotine," 12 Apr. 2018 The moisture vapor suspended in the air condenses on the cold coil. Roy Berendsohn, Popular Mechanics, "The DIY Guide To Fixing Your Leaky Air Conditioner," 15 Mar. 2019 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

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

19 Apr 2019

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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

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