Meaning of “gas” - Learner’s Dictionary

gas

noun uk us /ɡæs/
SUBSTANCE [ C, U ]

B2 a substance in a form like air and not solid or liquid:

poisonous gases
FUEL [ U ]

A2 a substance in a form like air used as a fuel for heating and cooking:

UK a gas cooker/ US a gas stove
CAR FUEL [ U ] US (UK petrol)

a liquid fuel used in cars:

half a tank of gas
STOMACH [ U ] US (UK wind)

air in your stomach that makes you feel uncomfortable and sometimes makes noises

the gas US informal

the part of a car that you push with your foot to make it go faster:

We'd better step on the gas (= drive faster).
→ See also natural gas , tear gas

(Definition of “gas noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)