Merriam-Webster Collegiate Dictionary - rotation

 noun  Date: 1555  1.  a.  (1) the action or process of rotating on or as if on an axis or center  (2) the act or an instance of rotating something  b. one complete turn ; the angular displacement required to return a rotating body or figure to its original orientation  2.  a. return or succession in a series ~ of the seasons  b. the growing of different crops in succession in one field usually in a regular sequence  3. the turning of a body part about its long axis as if on a pivot  4. a game of pool in which all 15 object balls are shot in numerical order  5. the series of pitchers on a baseball team who regularly start successive games in turn  • ~al adjective