润滑油 rùnhuáyóu lubricating oil Origin Definitions Defs Strokes Stroke Words Sentences Sents 润滑 潤滑 rùnhuá noun to lubricate to apply oil, grease, or other substances to surfaces in contact to reduce friction and wear油 yóu noun oil oil; fat; grease; any of various liquid fats or hydrocarbons used as food, fuel, or lubricants