gas

American  

[gas] / gæs /

noun

gases, plural gasses plural

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)

gasses, present (3rd person singular) gassed, past participle, past gassing present participle

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.

verb (used without object)

gasses, present (3rd person singular) gassed, past participle, past gassing present participle

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 byup ).

verb phrase

1. gas up to fill the gasoline tank of an automobile, truck, or other vehicle.

idioms

1. step on the gas, 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.

gas British  

/ ɡæs /

noun

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 phase Compare liquid solid

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 alone Compare vapour

4. 1. a fossil fuel in the form of a gas, used as a source of domestic and industrial heat See also coal gas natural gas

   2. ( as modifier )

      a gas cooker

      gas fire

5. a gaseous anaesthetic, such as nitrous oxide

6. mining firedamp or the explosive mixture of firedamp and air

7. the usual US, Canadian, and New Zealand word for petrol See also gasoline

8. informal

   1. to increase the speed of a motor vehicle; accelerate

   2. to hurry

9. a toxic or suffocating substance in suspension in air used against an enemy

10. informal idle talk or boasting

11. slang a delightful or successful person or thing

    his latest record is a gas

12. an informal name for flatus

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verb

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. informal to talk in an idle or boastful way (to a person)

6. slang (tr) to thrill or delight

gas Scientific  

/ găs /

1. One of four main states of matter, composed of molecules in constant random motion. Unlike a solid, a gas has no fixed shape and will take on the shape of the space available. Unlike a liquid, the intermolecular forces are very small; it has no fixed volume and will expand to fill the space available.

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gas Cultural  

1. 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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gas More Idioms  

More idioms and phrases containing gas

• cook with gas
• run out of steam (gas)

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Other Word Forms

Derived Forms

• nongas
  noun
• gasless
  adjective

Inflected Forms

Nouns

• gases
  plural
• gasses
  plural

Participles

• gassing
  present
• gassed
  past

Conjugated Forms

Present

• gas
  simple
• gasses
  simple
• have gassed
  perfect
• has gassed
  perfect
• am gassing
  progressive
• are gassing
  progressive
• is gassing
  progressive
• have been gassing
  perfect progressive
• has been gassing
  perfect progressive

Past

• gassed
  simple
• had gassed
  perfect
• was gassing
  progressive
• were gassing
  progressive
• had been gassing
  perfect progressive

Future

• will gas
  simple
• will have gassed
  perfect
• will be gassing
  progressive
• will have been gassing
  perfect progressive

Etymology

Origin of gas

First recorded in 1650–60; coined by J. B. van Helmont (1577–1644), Flemish chemist; suggested by Greek cháos “atmosphere”

Explanation

Matter can be found in solid, liquid, or gas form. The air you breathe in and the carbon dioxide you breathe out, are both examples of gas. Gasoline is a kind of a gas that you use as car fuel, and when people say they need gas, usually this is the kind they're talking about. They're probably not talking about the digestive kind of gas that causes you to fart. There are poisons that can be released as gas, and you might hear about riot police somewhere gassing people: spraying them with harmful gas. Gas has no fixed shape and changes density easily.

Example Sentences

See Examples For:

gas gases gasses gassed gassing

Centrifuges are machines that are used to spin uranium gas, separating isotopes to enrich the material for civilian nuclear energy or potential weapons production.

From The Wall Street Journal ● Jul. 21, 2026

"Don't be surprised when the gas comes your way," quipped Julius Maada Bio, Sierra Leone's president and the current head of West Africa regional bloc Ecowas, following Sunday evening's ceremony in Freetown.

From BBC ● Jul. 20, 2026

And the widening of that spread could have implications beyond the price for a gallon of gas, as some fear it could put pressure on the stock market as well.

From MarketWatch ● Jul. 20, 2026

That threat could introduce more turmoil into the global economy, as the waterway in question, the Bab al-Mandeb Strait, is an important shipping route for oil and natural gas.

From Slate ● Jul. 20, 2026

But as she prepared to turn onto their street, she hesitated, turned the car away, and hit the gas.

From "Boy 2.0" by Tracey Baptiste

Protecting the Amazon is crucial to combat climate change, since its dense vegetation absorbs the greenhouse gases that cause global warming.

From Barron's ● Jul. 21, 2026

The datasets, gathered over decades, contain vital information about Earth systems, including greenhouse gases, clouds, precipitation and ice sheets.

From Barron's ● Jul. 20, 2026

But there may be other, more life-sustaining gases, lower down.

From BBC ● Jul. 17, 2026

“That refusal forces victims to pay their own way out, and leaves those who can’t afford to leave trapped in gases and toxins that no agency will name.”

From Los Angeles Times ● Jul. 14, 2026

Or we provide our own radioactively labeled gases and see if they are converted into organic matter, in which case small Martians are inferred.

From "Cosmos" by Carl Sagan

The gas detected in the atmosphere is helium, which would not be able to support life, but other gasses may also be present.

From BBC ● Jul. 17, 2026

We found the defects can make the graphene more "sticky" to other materials, making it more useful as a catalyst, as well as improving its capability of detecting different gasses for use in sensors.

From Science Daily ● Dec. 4, 2025

As carbon dioxide and other greenhouse gasses build up in the dense lower atmosphere, they absorb heat and keep it trapped there.

From Salon ● Apr. 12, 2025

Unlike visible light, radio waves from hot gasses are not blocked that easily by cosmic dust.

From Space Scoop ● Mar. 27, 2025

The regulator analyzes the air with spectroscopy, then separates the gasses by supercooling them.

From "The Martian" by Andy Weir

Morris’s mother and father, respectively, were an accomplished organist and a mechanic who had been gassed in World War I. Like Waugh, Morris boarded as a teenager at Lancing College in West Sussex, England.

From The Wall Street Journal ● Apr. 23, 2026

“I’m not sure why Taylor picked such a rundown place to film, but I’m gassed about it,” said Hogg, 24.

From The Wall Street Journal ● Mar. 5, 2026

He uploaded his first song, Plethora, to TiKTok in 2019 and was "gassed" when it received 1,000 plays in a day.

From BBC ● Jan. 8, 2026

That said, they loved the way the game was decided, with the Detroit offensive line finally imposing its will on a gassed Rams defense.

From Los Angeles Times ● Sep. 9, 2024

Shannon gassed the joke up like he always did whenever it wasn’t about him.

From "All American Boys" by Jason Reynolds

The rest stop duration may require a bit more time than gassing up, and that is an added safety factor on a road trip.

From The Wall Street Journal ● Jul. 12, 2026

Some travelers say they can’t afford not to travel, however, so they’re putting all options on the table — from booking rail tickets to gassing up their cars.

From MarketWatch ● Nov. 8, 2025

In addition, the method used to kill the infected chickens — carbon dioxide gassing — required that workers move “from chicken to chicken” increasing their “degree of interaction with each potentially infected bird.”

From Los Angeles Times ● Jul. 16, 2024

Last week, the UN's High Commissioner for Human Rights urged a halt to the execution, saying that gassing Smith could amount to torture or other cruel, inhuman or degrading treatment under international human rights law.

From BBC ● Jan. 25, 2024

But Ella's family didn't believe in gassing you up.

From "The Marvellers" by Dhonielle Clayton

Related Words

• smoke
• vapor