vapor
Americannoun
-
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.
-
Physics. a gas at a temperature below its critical temperature.
-
a substance converted into a gaseous state for technical or medicinal uses.
-
a combination of gaseous particles of a substance and air.
-
Archaic. vapors,
-
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.
-
-
Often Facetious. the vapors. a feeling of being overwhelmed with strong emotion.
That guy gives the press the vapors every time he announces a new project.
-
Archaic.
-
a strange, senseless, or fantastic notion.
-
something insubstantial or transitory.
-
verb (used with object)
-
to cause to rise or pass off in, or as if in, vapor; vaporize.
-
Archaic. to affect with the vapors; depress.
verb (used without object)
-
to rise or pass off in the form of vapor.
-
to emit vapor or exhalations.
-
to talk or act grandiloquently, pompously, or boastfully; bluster.
noun
-
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
-
A faintly visible suspension of fine particles of matter in the air, as mist, fumes, or smoke.
-
A mixture of fine droplets of a substance and air, as the fuel mixture of an internal-combustion engine.
Usage
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 Word Forms
- vaporability noun
- vaporable adjective
- vaporer noun
- vaporless adjective
- vaporlike adjective
Etymology
Origin of vapor
First recorded in 1325–75; Middle English vapour, from Latin vapor “steam,” of uncertain origin; akin to vapidus vapid ( def. ) and vappa “wine that has gone flat”; perhaps cognate with Greek kapnós “smoke” ( acapnia ( def. ) )
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
These microscopic pores act like adjustable valves, letting carbon dioxide enter the leaf for photosynthesis while allowing water vapor to escape into the air.
From Science Daily
Each year, wildfires burn through vast areas of vegetation, sending a complex mixture of water vapor, ash, and carbon-based chemicals into the atmosphere.
From Science Daily
This design offers a key advantage over conventional hollow-core fibers, which can take months to fill with atomic vapor.
From Science Daily
These plumes lift potentially harmful chemicals, aerosol pollutants, and water vapor hundreds of feet into the air -- all factors that can enhance warming.
From Science Daily
A familiar physical example appears at the critical point of water, defined by a precise temperature and pressure at which liquid water and water vapor become indistinguishable.
From Science Daily
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
