The Collaborative International Dictionary of English v.0.48:
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.
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   2. Any return or succesion in a series.
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   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.
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