Source : Webster's Revised Unabridged Dictionary (1913)

Rotation \Ro*ta"tion\, n. [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.

Rotation \Ro*ta"tion\, a.
   Pertaining to, or resulting from, rotation; of the nature of,
   or characterized by, rotation; as, rotational velocity.

Source : WordNet®

rotation
     n 1: the act of rotating as if on an axis; "the rotation of the
          dancer kept time with the music" [syn: {rotary motion}]
     2: (mathematics) a transformation in which the coordinate axes
        are rotated by a fixed angle about the origin
     3: a single complete turn (axial or orbital); "the plane made
        three rotations before it crashed"; "the revolution of the
        earth about the sun takes one year" [syn: {revolution}, {gyration}]
     4: a planned recurrent sequence (of crops or personnel etc.);
        "crop rotation makes a balanced demand on the fertility of
        the soil"; "the manager had only four starting pitchers in
        his rotation"