*oil¹/ɔɪl; ɔɪl/ n [U] 1 a thick dark liquid from under the ground, used to make petrol 石油: the big oil companies 大的石油公司 2 a thick liquid used to make the parts of machines move more easily 〔机器的〕润滑油 3 a liquid made from plants or animal fat, used in cooking 〔烹调用的〕植物油; 油: olive oil 橄榄油