n. The act of rotating or turning, or the state of being whirled round; the continuous motion of a solid body, as a wheel or sphere, about an axis, its opposite sides moving relatively to one another, as distinguished from the forward motion of the whole body in a circle or an ellipse independent of any relative motion of its parts, as that of the planets.n. A peculiar spiral movement of fluids observed within the cavity of certain vegetable cells, as in Chara and Vallisneria. See below.n. Serial or recurrent order; a round or sequence of one after another; a fixed or definite routine of succession; regularly recurring change.n. In forestry, the period represented by the age of a forest, or a part of a forest, at the time when it is cut, or intended to be cut.