rotation

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act or process of turning around a center or an axis: the axial rotation of the earth.
2. n. A single complete cycle of such motion.
3. n. Mathematics A transformation of a coordinate system in which the new axes have a specified angular displacement from their original position while the origin remains fixed.
4. n. Regular and uniform variation in a sequence or series: a rotation of personnel; crop rotation.
5. n. Games An order of shooting balls in billiards in which the ball with the lowest number on the table is always pocketed first.

Century Dictionary and Cyclopedia

1. 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. Thus, the daily turning of the earth on its axis is a rotation; its annual motion round the sun is a revolution.
2. n. A peculiar spiral movement of fluids observed within the cavity of certain vegetable cells, as in Chara and Vallisneria. See below.
3. n. Serial or recurrent order; a round or sequence of one after another; a fixed or definite routine of succession; regularly recurring change.
4. 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.

Wiktionary

1. n. The act of turning around a centre or an axis.
2. n. A single complete cycle around a centre or an axis.
3. n. A regular variation in a sequence.
4. n. mathematics An isometry that fixes precisely one point.
5. n. baseball The set of starting pitchers of a team.
6. n. aviation The step during takeoff when the pilot commands the vehicle to lift the nose wheel off the ground during the takeoff roll.

GNU Webster's 1913

1. n. The act of turning, as a wheel or a solid body on its axis, as distinguished from the progressive motion of a revolving round another body or a distant point; thus, the daily turning of the earth on its axis is a rotation; its annual motion round the sun is a revolution.
2. n. Any return or succesion in a series.
3. adj. Pertaining to, or resulting from, rotation; of the nature of, or characterized by, rotation.

WordNet 3.0

1. n. a planned recurrent sequence (of crops or personnel etc.)
2. n. a single complete turn (axial or orbital)
3. n. (mathematics) a transformation in which the coordinate axes are rotated by a fixed angle about the origin
4. n. the act of rotating as if on an axis