页岩油 yèyányóu shale oil Origin Definitions Defs Strokes Stroke Words Sentences Sents 页岩 頁岩 yèyán shale a type of sedimentary rock formed from mud or clay that splits easily into thin layers油 yóu noun oil oil; fat; grease; any of various liquid fats or hydrocarbons used as food, fuel, or lubricants