Meaning of “fuel” - Learner’s Dictionary

fuel

noun [ C, U ] us uk /ˈfjuːəl/
nuclear fuelHow long will it be before the world's fuel supplies are exhausted?The tanker contained 40 000 litres of fuel.There's been a dramatic rise in fuel costs.Fuel is very expensive in this country.

B1 a substance that is burned to provide heat or power:

The plane ran out of fuel and had to land at sea.
fuel bills

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