The Collaborative International Dictionary of English v.0.48:

Govern \Gov"ern\, v. t. [imp. & p. p. Governed; p. pr. & vb.
   n. Governing.] [OF. governer, F. gouverner, fr. L.
   gubernare to steer, pilot, govern, Gr. kyberna^n. Cf.
   Gubernatorial.]
   1. To direct and control, as the actions or conduct of men,
      either by established laws or by arbitrary will; to
      regulate by authority. "Fit to govern and rule
      multitudes." --Shak.
      [1913 Webster]

   2. To regulate; to influence; to direct; to restrain; to
      manage; as, to govern the life; to govern a horse.
      [1913 Webster]

            Govern well thy appetite.             --Milton.
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   3. (Gram.) To require to be in a particular case; as, a
      transitive verb governs a noun in the objective case; or
      to require (a particular case); as, a transitive verb
      governs the objective case.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Governing \Gov"ern*ing\, a.
   1. Holding the superiority; prevalent; controlling; as, a
      governing wind; a governing party in a state. --Jay.
      [1913 Webster]

   2. (Gram.) Requiring a particular case.
      [1913 Webster]

WordNet (r) 3.0 (2006):

governing
    adj 1: responsible for making and enforcing rules and laws;
           "governing bodies"
    n 1: the act of governing; exercising authority; "regulations
         for the governing of state prisons"; "he had considerable
         experience of government" [syn: government, governing,
         governance, government activity, administration]