Tur″bine (?), n. [L. turbo, -inis, that which spins or whirls round, whirl.] 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.
☞ In some turbines, the water is supplied to the wheel from below, instead of above. Turbines in which the water flows in a direction parallel to the axis are called parallel-flow turbines.