gases

IPA/ɡæs/
KK[ɡˈæsəz]IPA/ɡæs/

gases — noun

  • gasessingular
  • gasesesplural

1. a substance that has no fixed shape or volume and naturally spreads out to fill

1.nounA2
Definition

a substance that has no fixed shape or volume and naturally spreads out to fill any container it is placed in — oxygen, carbon dioxide, and nitrogen are examples of gases that make up the air we breathe

Example

Carbon dioxide is a gas that plants use during photosynthesis.

uncountable, naming a specific gas

The factory released several harmful gases into the atmosphere.

plural: different types of gas

Common collocations
  • poisonous gas
  • toxic gas
  • greenhouse gases
  • natural gas
  • gas molecules
  • gas particles
  • gas pressure
Synonyms
  • vapor

    usually refers to a substance that is liquid or solid at room temperature but has become gaseous; more specific than 'gas'

  • fume

    a gas or vapor that smells strongly or is harmful; always plural in this sense

Antonyms
  • solid

    matter with a fixed shape and volume

  • liquid

    matter that flows but has a fixed volume

Usage Note

Countable when referring to specific chemical types (e.g. 'greenhouse gases'), uncountable as a general state of matter ('Gas has no fixed volume').

Common Mistakes

A gas is one of the state of matters.
A gas is one of the states of matter.
'state of matter' is the correct fixed phrase.
The air is a mixture of gas.
The air is a mixture of gases.
use the plural when naming different types.

2. a type of fuel that comes from the ground and is burned to produce heat for cook

2.nounA2
Definition

a type of fuel that comes from the ground and is burned to produce heat for cooking, heating buildings, or powering equipment

Example

Mizuki turned on the gas and put the kettle on for tea.

uncountable: fuel for cooking

Their apartment building uses gas for heating and hot water.

gas for heating

Common collocations
  • gas stove
  • gas oven
  • gas heater
  • gas bill
  • gas leak
  • gas pipe
  • turn on the gas
  • turn off the gas
  • natural gas
Synonyms
  • natural gas

    the full name for the fuel extracted from the ground

Usage Note

Commonly modified by 'natural' to distinguish from other fuel types. 'Gas' without a modifier usually refers to natural gas in British English contexts.

Common Mistakes

I cook with a gas.
I cook with gas.
'gas' as a fuel is uncountable.

3. a substance in the form of a vapor that is breathed in through a mask to make a

3.nounB2
Definition

a substance in the form of a vapor that is breathed in through a mask to make a patient unconscious or unable to feel pain during a medical operation

Example

The anesthetist gave the patient gas through a mask before the surgery began.

medical context: gas + mask

Jiwoo felt dizzy as the gas took effect, then remembered nothing until she woke up.

Common collocations
  • anesthetic gas
  • laughing gas
  • gas mask
  • gas and air
  • put someone under gas
Synonyms
  • anesthetic

    the general term for any drug that prevents pain during surgery; 'gas' is a specific type

Usage Note

In informal conversation, 'gas' can refer to nitrous oxide ('laughing gas') used at the dentist. In medical writing, specific names like 'sevoflurane' or 'nitrous oxide' are preferred.

4. air or other gases that build up in the stomach or intestines, often causing dis

4.nounB1
Definition

air or other gases that build up in the stomach or intestines, often causing discomfort, bloating, or the need to release it from the body

Example

Eating beans can give you gas, but soaking them overnight helps reduce it.

collocation: give someone gas

The baby had gas after feeding and cried until Heather gently patted her back.

baby gas: common context

Common collocations
  • have gas
  • get gas
  • give someone gas
  • gas pain
  • pass gas
  • trapped gas
  • relieve gas
Synonyms
  • wind

    the common British English term for gas in the digestive system

  • bloating

    the uncomfortable feeling of having too much gas in the stomach, not the gas itself

Usage Note

Considered a sensitive topic in some social contexts. In polite conversation, 'wind' (British) or 'gas' (American) is used instead of more graphic terms.

Common Mistakes

I have a gas in my stomach.
I have gas in my stomach.
'gas' in this sense is uncountable.
The baby has gases.
The baby has gas.
uncountable even when referring to a lot of it.

5. a liquid fuel refined from crude oil that powers the engines of cars, trucks, an

5.nounA2
Definition

a liquid fuel refined from crude oil that powers the engines of cars, trucks, and other road vehicles — short for 'gasoline'

Example

Eli stopped at the station to put gas in the car before the long drive.

collocation: put gas in the car

The price of gas went up by twenty cents per liter this week.

collocation: price of gas

Common collocations
  • fill up with gas
  • put gas in
  • run out of gas
  • gas station
  • gas tank
  • gas pedal
  • premium gas
  • regular gas
  • a gallon of gas
Synonyms
  • gasoline

    the full, more formal name for the fuel; 'gas' is the shortened everyday form

  • petrol

    the British English equivalent

Usage Note

This sense is almost exclusively American English. In British English, the fuel is called 'petrol'. The word 'gas' in the UK means the cooking/heating fuel (sense 2).

Common Mistakes

I need to fill gas.
I need to fill up with gas' or 'I need to get gas.
'fill' requires a particle or different verb pattern.
I put petrol in my car' (in an American context).
Use 'gas' in the US; 'petrol' in the UK.

6. the pedal in a car or truck that you push down to increase the vehicle's speed —

6.nounB1
Definition

the pedal in a car or truck that you push down to increase the vehicle's speed — short for 'gas pedal'

Example

Inês pressed the gas gently as she merged onto the freeway.

collocation: press the gas

The instructor told the student to take his foot off the gas when approaching the red light.

collocation: foot off the gas

Common collocations
  • step on the gas
  • hit the gas
  • press the gas
  • take your foot off the gas
  • floor the gas
Synonyms
  • accelerator

    the formal term for the pedal; used in all varieties of English

  • throttle

    technical term for the valve that controls fuel flow, also used to mean the accelerator in some contexts

Antonyms
  • brake

    the pedal that slows or stops the vehicle

Usage Note

Always used with 'the' ('the gas'). In British English, this is called 'the accelerator' or 'the throttle'. 'Step on the gas' also has a figurative meaning meaning 'hurry up'.

Common Mistakes

Push the gas pedal to stop the car.
Push the brake to stop the car.
the gas makes the car go; the brake stops it.

7. an experience or activity that is very enjoyable, amusing, or exciting — used in

7.nounC1
Definition

an experience or activity that is very enjoyable, amusing, or exciting — used in informal expressions like 'a gas' or 'good gas'

Example

The street festival with live music and food stalls was a real gas.

phrase: a real gas

Esme said the comedy show was a gas and that we should all go next time.

Common collocations
  • a gas
  • a real gas
Synonyms
  • fun

    the standard, neutral word for enjoyment; 'a gas' is more informal and slightly dated

  • a blast

    a common modern slang equivalent that still sounds current

Antonyms
  • a drag

    slang for something boring or unpleasant

Usage Note

This slang sense peaked in mid-20th-century American English and sounds dated to younger speakers. It is still understood but not commonly used in everyday conversation today.

Common Mistakes

The party was gas.
The party was a gas.
'a' is required before 'gas' in this slang sense.

8. in baseball, the quality of throwing a ball at very high speed, especially from

8.nounC1
Definition

in baseball, the quality of throwing a ball at very high speed, especially from the pitcher to the batter

Example

The rookie pitcher throws serious gas, regularly hitting ninety-eight miles per hour.

phrase: throws gas

Scouts came from three teams to watch him throw gas at the championship game.

Common collocations
  • throw gas
  • throw some gas
Synonyms
  • heat

    an equally common baseball slang term for a very fast pitch

  • smoke

    another baseball slang word for a fast, powerful pitch

Antonyms
  • changeup

    a slow pitch meant to surprise the batter after faster pitches

Usage Note

Baseball slang only. 'Throw gas' means to pitch a very fast fastball. 'Gas' in this sense is sometimes replaced by 'heat' ('throw heat') or 'smoke' ('throw smoke').

gases — verb

Word family

Synonym discussion

Sense: noun/1

'Gas' is the broadest term for any substance in an aeriform state that fills its container. 'Vapor' refers specifically to a substance that is normally liquid or solid at room temperature but has become gaseous — water vapor is the classic example. 'Fume' adds a negative connotation of being harmful or irritating, and is almost always plural: 'exhaust fumes'. 'Steam' is the visible vapor given off by boiling water, and 'air' is the specific mixture of gases that surrounds Earth. For everyday use: if you cannot see it and it is not water-based, call it 'gas'. If you can see it rising from something hot, it is probably 'steam' or 'vapor'. If it smells bad or might hurt you, it is 'fumes'. For example, you breathe in 'air', cook with 'gas', see 'steam' from a kettle, worry about chemical 'fumes' in a lab, and watch 'water vapor' rise from a warm road after rain.

Common collocations

Nouns

  • gas pressure
  • gas supply
  • gas emissions
  • gas leak

Phrases

  • a mixture of gases
  • a cloud of gas
  • convert into gas

Prepositions

  • gas from [source]
  • gas in [place]

Etymology

GreekLatin/DutchFrenchEnglish

The word 'gas' was coined in the 17th century by the Flemish chemist Jan Baptist van Helmont. He deliberately invented a new term based on the Greek word 'khaos' (χάος), meaning 'empty space' or 'chaos', because he felt that gases were elusive, chaotic substances that could not be held in a fixed shape. The word entered English via French ('gaz') and gradually came to refer to any substance in the aeriform state. The slang senses ('a gas' meaning fun, 'throw gas' in baseball) emerged in 20th-century American English.

First known use

1779

1779, in the meaning defined at sense 1 Verb