rotationn.[L. rotatio: cf. F. rotation.]1. 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. Any return or succesion in a series.()Moment of rotation. See Moment of inertia, under Moment. -- Rotation in office, the practice of changing public officers at frequent intervals by discharges and substitutions. -- Rotation of crops, the practices of cultivating an orderly succession of different crops on the same land.()a. Pertaining to, or resulting from, rotation; of the nature of, or characterized by, rotation; as, rotational velocity.()