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See more synonyms for gas on Thesaurus.com
noun, plural gas·es or gas·ses.
  1. Physics. a substance possessing perfect molecular mobility and the property of indefinite expansion, as opposed to a solid or liquid.
  2. any such fluid or mixture of fluids.
  3. any such fluid used as an anesthetic, as nitrous oxide: Did the dentist give you gas for your extraction?
  4. any such combustible fluid used as fuel: Light the gas in the oven.
  5. Automotive.
    1. gasoline.
    2. Also called gas pedal.the foot-operated accelerator of an automotive vehicle: Take your foot off the gas.
  6. flatus.
  7. Coal Mining. an explosive mixture of firedamp with air.
  8. an aeriform fluid or a mistlike assemblage of fine particles suspended in air, used in warfare to asphyxiate, poison, or stupefy an enemy.
  9. Slang.
    1. empty talk.
    2. a person or thing that is very entertaining, pleasing, or successful: The party was an absolute gas, and we loved it.
    3. a person or thing that affects one strongly.
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verb (used with object), gassed, gas·sing.
  1. to supply with gas.
  2. to overcome, poison, or asphyxiate with gas or fumes.
  3. to singe (yarns or fabrics) with a gas flame to remove superfluous fibers.
  4. to treat or impregnate with gas.
  5. Slang.
    1. to talk nonsense or falsehood to.
    2. to amuse or affect strongly: Her weird clothes really gas me.
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verb (used without object), gassed, gas·sing.
  1. to give off gas, as a storage battery being charged.
  2. Slang.
    1. to indulge in idle, empty talk.
    2. to become drunk (often followed by up).
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Verb Phrases
  1. gas up, to fill the gasoline tank of an automobile, truck, or other vehicle.
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  1. step on the gas, Informal. to increase the speed of one's movement or activity; hurry: We'd better step on the gas or we'll be late for the concert.
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Origin of gas

1650–60; coined by J. B. van Helmont (1577–1644), Flemish chemist; suggested by Greek cháos atmosphere
Related formsgas·less, adjectivenon·gas, noun, plural non·gas·es.
Can be confusedfluid gas liquid (see synonym study at liquid)


  1. a Kwa language of Ghana, spoken in Accra and vicinity.
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Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for gas

Contemporary Examples

Historical Examples

  • Under the gas chandelier, he straightened and threw out his arms.


    Mary Roberts Rinehart

  • The thought of the gas office and its deadly round sickened him.


    Mary Roberts Rinehart

  • Sidney had lighted the gas and was throwing on her dressing-gown.


    Mary Roberts Rinehart

  • Gas is indispensable in the operation of dirigible balloons, and gas is expensive.

    Flying Machines

    W.J. Jackman and Thos. H. Russell

  • Of acid it would take 60 times the weight of the gas, or nearly 76 tons.

    Flying Machines

    W.J. Jackman and Thos. H. Russell

British Dictionary definitions for gas


noun plural gases or gasses
  1. a substance in a physical state in which it does not resist change of shape and will expand indefinitely to fill any container. If very high pressure is applied a gas may become liquid or solid, otherwise its density tends towards that of the condensed phaseCompare liquid (def. 1), solid (def. 1)
  2. any substance that is gaseous at room temperature and atmospheric pressure
  3. any gaseous substance that is above its critical temperature and therefore not liquefiable by pressure aloneCompare vapour (def. 2)
    1. a fossil fuel in the form of a gas, used as a source of domestic and industrial heatSee also coal gas, natural gas
    2. (as modifier)a gas cooker; gas fire
  4. a gaseous anaesthetic, such as nitrous oxide
  5. mining firedamp or the explosive mixture of firedamp and air
  6. the usual US, Canadian, and New Zealand word for petrol See also gasoline
  7. step on the gas informal
    1. to increase the speed of a motor vehicle; accelerate
    2. to hurry
  8. a toxic or suffocating substance in suspension in air used against an enemy
  9. informal idle talk or boasting
  10. slang a delightful or successful person or thinghis latest record is a gas
  11. US an informal name for flatus
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verb gases, gasses, gassing or gassed
  1. (tr) to provide or fill with gas
  2. (tr) to subject to gas fumes, esp so as to asphyxiate or render unconscious
  3. (intr) to give off gas, as in the charging of a battery
  4. (tr) (in textiles) to singe (fabric) with a flame from a gas burner to remove unwanted fibres
  5. (intr foll by to) informal to talk in an idle or boastful way (to a person)
  6. (tr) slang, mainly US and Canadian to thrill or delight
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Derived Formsgasless, adjective

Word Origin

C17 (coined by J. B. van Helmont (1577–1644), Flemish chemist): modification of Greek khaos atmosphere


the internet domain name for
  1. Gabon
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the chemical symbol for
  1. gallium
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  1. plural Ga, Gas, or Gãs a member of a Negroid people of W Africa living chiefly in S Ghana
  2. the language of this people, belonging to the Kwa branch of the Niger-Congo family
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abbreviation for
  1. General Assembly (of the United Nations)
  2. general average
  3. Georgia
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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

Word Origin and History for gas


1650s, from Dutch gas, probably from Greek khaos "empty space" (see chaos). The sound of Dutch "g" is roughly equivalent to that of Greek "kh." First used by Flemish chemist J.B. van Helmont (1577-1644), probably influenced by Paracelsus, who used khaos in an occult sense of "proper elements of spirits" or "ultra-rarified water," which was van Helmont's definition of gas.

Modern scientific sense began 1779, with later specialization to "combustible mix of vapors" (1794, originally coal gas); "anesthetic" (1894, originally nitrous oxide); and "poison gas" (1900). Meaning "intestinal vapors" is from 1882. "The success of this artificial word is unique" [Weekley]. Slang sense of "empty talk" is from 1847; slang meaning "something exciting or excellent" first attested 1953, from earlier hepster slang gasser in the same sense (1944). Gas also meant "fun, a joke" in Anglo-Irish and was used so by Joyce (1914). As short for gasoline, it is American English, first recorded 1905.

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1886, "to supply with gas," from gas (n.). Sense of "poison with gas" is from 1889 as an accidental thing, from 1915 as a military attack. Related: Gassed; gassing.

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Online Etymology Dictionary, © 2010 Douglas Harper

gas in Medicine


n. pl. gas•es
  1. The state of matter distinguished from the solid and liquid states by relatively low density and viscosity, relatively great expansion and contraction with changes in pressure and temperature, the ability to diffuse readily, and the spontaneous tendency to become distributed uniformly throughout any container.
  2. A substance in the gaseous state.
  3. A gaseous fuel, such as natural gas.
  4. Gasoline.
  5. A gaseous asphyxiant, an irritant, or a poison.
  6. A gaseous anesthetic, such as nitrous oxide.
  7. Flatulence.
  8. Flatus.
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  1. To treat chemically with gas.
  2. To overcome, disable, or kill with poisonous fumes.
  3. To give off gas.
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  1. The symbol for the elementgallium

gas in Science


Related formsgaseous adjective (găsē-əs, găshəs)


gas in Culture


In physics, one of the phases of matter. The atoms or molecules in gases are more widely spaced than in solids or liquids and suffer only occasional collisions with one another.

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The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Idioms and Phrases with gas


In addition to the idiom beginning with gas

  • gas up

also see:

  • cook with gas
  • run out of steam (gas)
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The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.