The Collaborative International Dictionary of English v.0.48:

Proprietary \Pro*pri"e*ta*ry\, n.; pl. Proprietaries. [L.
   proprietarius: cf. F. propri['e]taire. See Propriety, and
   cf. Proprietor.]
   1. A proprietor or owner; one who has exclusive title to a
      thing; one who possesses, or holds the title to, a thing
      in his own right. --Fuller.
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   2. A body proprietors, taken collectively.
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   3. (Eccl.) A monk who had reserved goods and effects to
      himself, notwithstanding his renunciation of all at the
      time of profession.
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