vapor

1 of 2

noun

va·​por ˈvā-pər 

1

: diffused matter (such as smoke or fog) suspended floating in the air and impairing its transparency

2

a

: 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

3

a

: 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

vapor

2 of 2

verb

vapored; vaporing ˈvā-p(ə-)riŋ 

intransitive verb

1

a

: to rise or pass off in vapor

b

: to emit vapor

2

: to indulge in bragging, blustering, or idle talk

vaporer

ˈvā-pər-ər 

noun

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.

Synonyms

Verb

• boast
• brag
• blow
• display

Examples of vapor in a Sentence

Verb

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

Recent Examples on the Web

Noun

Also featured are Alta Resource Technologies, using computational biochemistry to extract critical minerals like neodymium and gallium from e-waste, and Tidal Metals, which is pioneering magnesium extraction from seawater through a novel vapor adsorption system. —Felicia Jackson, Forbes.com, 1 July 2025

One of its more unique features is a cool mist mode, which blows out cold vapor when the water tank is filled with ice cubes. —Toni Sutton, People.com, 28 June 2025

Verb

Scorching flames turn it to vapor and keep heating that steam to more than 400 degrees Fahrenheit before sending it out around Manhattan. —Patrick McGeehan, New York Times, 2 Apr. 2024

Nasal decongestant vapor inhaler: A nasal inhaler is a decongestant formula used to inhale for relief. —Daley Quinn, Health, 26 Apr. 2024

Word History

Etymology

Noun

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"

First Known Use

Noun

14th century, in the meaning defined at sense 1

Verb

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

Phrases Containing vapor

• mercury-vapor lamp
• sodium-vapor lamp
• vapor barrier
• vapor lock
• vapor pressure
• vapor trail
• water vapor

Rhymes for vapor

• caper
• paper
• raper
• scraper
• shaper
• taper
• newspaper
• notepaper
• sandpaper
• skyscraper
• wallpaper
• wastepaper

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Kids Definition

vapor

noun

va·​por

ˈvā-pər

1

: fine particles of matter (as fog or smoke) floating in the air and clouding it

2

: a substance in the gaseous state

Medical Definition

vapor

noun

va·​por

variants or chiefly British vapour

ˈvā-pər 

1

a

: 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