n. A water wheel, commonly horizontal, variously constructed, but usually having a series of curved floats or buckets, against which the water acts by its impulse or reaction in flowing either outward from a central chamber, inward from an external casing, or from above downward, etc.; -- also called turbine wheel.n. A type of rotary engine with a set of rotating vanes, diagonally inclined and often curved, attached to a central spindle, and obtaining its motive force from the passage of a fluid, as water, steam, combusted gases, or air, over the vanes. Water turbines are frequently used for generating power at hydroelectric power stations, and steam turbines are used for generating power from coal- or oil-fired electric power stations. Turbines are also found in jet engines, and in some automobile engines.