The Collaborative International Dictionary of English v.0.48:

Mastery \Mas"ter*y\, n.; pl. Masteries. [OF. maistrie.]
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   1. The position or authority of a master; dominion; command;
      supremacy; superiority.
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            If divided by mountains, they will fight for the
            mastery of the passages of the tops.  --Sir W.
                                                  Raleigh.
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   2. Superiority in war or competition; victory; triumph;
      preeminence.
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            The voice of them that shout for mastery. --Ex.
                                                  xxxii. 18.
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            Every man that striveth for the mastery is temperate
            in all things.                        --1 Cor. ix.
                                                  25.
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            O, but to have gulled him
            Had been a mastery.                   --B. Jonson.
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   3. Contest for superiority. [Obs.] --Holland.
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   4. A masterly operation; a feat. [Obs.]
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            I will do a maistrie ere I go.        --Chaucer.
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   5. Specifically, the philosopher's stone. [Obs.]
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   6. The act process of mastering; the state of having
      mastered.
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            He could attain to a mastery in all languages.
                                                  --Tillotson.
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            The learning and mastery of a tongue, being
            unpleasant in itself, should not be cumbered with
            other difficulties.                   --Locke.
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