Source : Webster's Revised Unabridged Dictionary (1913)

Mastery \Mas"ter*y\, n.; pl. {Masteries}. [OF. maistrie.]
   1. The position or authority of a master; dominion; command;
      supremacy; superiority.

            If divided by mountains, they will fight for the
            mastery of the passages of the tops.  --Sir W.
                                                  Raleigh.

   2. Superiority in war or competition; victory; triumph;
      pre["e]minence.

            The voice of them that shout for mastery. --Ex.
                                                  xxxii. 18.

            Every man that striveth for the mastery is temperate
            in all things.                        --1 Cor. ix.
                                                  25.

            O, but to have gulled him Had been a mastery. --B.
                                                  Jonson.

   3. Contest for superiority. [Obs.] --Holland.

   4. A masterly operation; a feat. [Obs.]

            I will do a maistrie ere I go.        --Chaucer.

   5. Specifically, the philosopher's stone. [Obs.]

   6. The act process of mastering; the state of having
      mastered.

            He could attain to a mastery in all languages.
                                                  --Tillotson.

            The learning and mastery of a tongue, being
            unpleasant in itself, should not be cumbered with
            other difficulties.                   --Locke.

Source : WordNet®

mastery
     n 1: great skillfulness and knowledge of some subject or
          activity; "a good command of French" [syn: {command}, {control}]
     2: power to dominate or defeat; "mastery of the seas" [syn: {domination},
         {supremacy}]
     3: the act of mastering or subordinating someone [syn: {subordination}]