Source : Webster's Revised Unabridged Dictionary (1913)

Supremacy \Su*prem"a*cy\, n. [Cf. F. supr['e]matie. See
   {Supreme}.]
   The state of being supreme, or in the highest station of
   power; highest or supreme authority or power; as, the
   supremacy of a king or a parliament.

         The usurped power of the pope being destroyed, the
         crown was restored to its supremacy over spiritual men
         and causes.                              --Blackstone.

   {Oath supremacy}, an oath which acknowledges the supremacy of
      the sovereign in spiritual affairs, and renounced or
      abjures the supremacy of the pope in ecclesiastical or
      temporal affairs. [Eng.] --Brande & C.

Source : WordNet®

supremacy
     n : power to dominate or defeat; "mastery of the seas" [syn: {domination},
          {mastery}]