oil

noun (FUEL)

/ɔɪl/

Definition

B1 [U] petroleum (= the black oil obtained from under the Earth's surface from which petrol comes): drilling for oil the oil industryPetroleum products especially when used as fuelFuels B1 [U] a thick liquid that comes from petroleum, used as a fuel and for making parts of machines move easily: diesel/lubricating oilLubricationFuelsPetroleum products especially when used as fuel

(Definition of oil noun (FUEL) from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)