vapor

[ vey-per ]
See synonyms for: vaporvaporedvaporingvapors on Thesaurus.com

noun
  1. a visible exhalation, such as fog, mist, steam, smoke, or noxious gas, diffused through or suspended in the air: The vapors rising from the bogs smelled muddy.

  2. Physics. a gas at a temperature below its critical temperature.

  1. a substance converted into a gaseous state for technical or medicinal uses.

  2. a combination of gaseous particles of a substance and air.

  3. vapors, Archaic.

    • harmful exhalations formerly supposed to be produced within the body, especially in the stomach.

    • mental or physical illness, such as depression or hypochondria, formerly supposed to result from such exhalations, especially in women.

  4. the vapors. Often Facetious. a feeling of being overwhelmed with strong emotion: That guy gives the press the vapors every time he announces a new project.

  5. Archaic.

    • a strange, senseless, or fantastic notion.

    • something insubstantial or transitory.

verb (used with object)
  1. to cause to rise or pass off in, or as if in, vapor; vaporize.

  2. Archaic. to affect with the vapors; depress.

verb (used without object)
  1. to rise or pass off in the form of vapor.

  2. to emit vapor or exhalations.

  1. to talk or act grandiloquently, pompously, or boastfully; bluster.

Origin of vapor

1
First recorded in 1325–75; Middle English vapour, from Latin vapor “steam,” of uncertain origin; akin to vapidus vapid and vappa “wine that has gone flat”; perhaps cognate with Greek kapnós “smoke” (see acapnia )
  • Also especially British, va·pour .

Other words from vapor

  • va·por·a·ble, adjective
  • va·por·a·bil·i·ty [vey-per-uh-bil-i-tee], /ˌveɪ pər əˈbɪl ɪ ti/, noun
  • va·por·er, noun
  • va·por·less, adjective
  • va·por·like, adjective

Words Nearby vapor

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use vapor in a sentence

British Dictionary definitions for vapor

vapor

/ (ˈveɪpə) /


noun
  1. the US spelling of vapour

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for vapor

vapor

[ pər ]


  1. The gaseous state of a substance that is normally liquid or solid at room temperature, such as water that has evaporated into the air. See more at vapor pressure. See also water vapor.

  2. A faintly visible suspension of fine particles of matter in the air, as mist, fumes, or smoke.

  1. A mixture of fine droplets of a substance and air, as the fuel mixture of an internal-combustion engine.

usage For vapor

The words vapor and steam usually call to mind a fine mist, such as that in the jet of water droplets near the spout of a boiling teakettle or in a bathroom after a shower. Vapor and steam, however, refer to the gaseous state of a substance. The fumes that arise when volatile substances such as alcohol and gasoline evaporate, for example, are vapors. The visible stream of water droplets rushing out of a teakettle spout is not steam. As the gaseous state of water heated past its boiling point, steam is invisible. Usually, there is a space of an inch or two between the spout and the beginning of the stream of droplets. This space contains steam. The steam loses its heat to the surrounding air, then falls below the boiling point and condenses in the air as water droplets. All liquids and solids give off vapors consisting of molecules that have evaporated from the substance. In a closed system, the vapor pressure of these molecules reaches an equilibrium at which the substance evaporates from the liquid (or solid) and recondenses on it in equal amounts.

Other words from vapor

  • vaporize verb

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.