a fluid, usually of low viscosity, as oil, used in a hydraulic system.
noun 1. a process in which fractures in rocks below the earth’s surface are opened and widened by injecting chemicals and liquids at high pressure: used especially to extract natural gas or oil.
noun 1. an elevator operated by fluid pressure, especially one used for raising automobiles in service stations and garages.
noun 1. placer mining using a pressurized stream of water.
noun 1. a motor that converts the kinetic or potential energy of a fluid into mechanical energy.