ETYM French hydraulique, Latin hydraulicus, from Greek, a water organ; hydro water + aulos flute, pipe. Related to Hydra.
1. Moved or operated of effected by water.
2. Of or relating to the study of hydraulics.
3. Pertaining to moving fluids; pertaining to mechanical action of water; conveyed or worked by water.

Field of study concerned with utilizing the properties of water and other liquids, in particular the way they flow and transmit pressure, and with the application of these properties in engineering. It applies the principles of hydrostatics and hydrodynamics. The oldest type of hydraulic machine is the hydraulic press, invented by Joseph Bramah in England 1795. The hydraulic principle of pressurized liquid increasing mechanical efficiency is commonly used on vehicle braking systems, the forging press, and the hydraulic systems of aircraft and excavators.
A hydraulic press consists of two liquid-connected pistons in cylinders, one of narrow bore, one of large bore. A force applied to the narrow piston applies a certain pressure (force per unit area) to the liquid, which is transmitted to the larger piston. Because the area of this piston is larger, the force exerted on it is larger. Thus the original force has been magnified, although the smaller piston must move a great distance to move the larger piston only a little, hence mechanical efficiency is gained in force but lost in movement. + prikaži više