gas
noun
uk/ɡæs/ usplural gases or gasses [ C or U ] ENVIRONMENT
a substance in a form like air that is neither solid nor liquid:
Oxygen, hydrogen and nitrogen are all gases.
All EU countries are required to cut their emissions of greenhouse gases.
[ U ] NATURAL RESOURCES, TRANSPORT ( US also gasoline); ( UK petrol)
a liquid obtained from petroleum, used especially as fuel for cars and other vehicles:
It was getting late and we were nearly out of gas.
The price of gas seems to be getting higher and higher.
See also
greenhouse gas
natural gas