The Collaborative International Dictionary of English v.0.48:

Priory \Pri"o*ry\, n.; pl. Priories. [Cf. LL. prioria. See
   Prior, n.]
   A religious house presided over by a prior or prioress; --
   sometimes an offshoot of, an subordinate to, an abbey, and
   called also cell, and obedience. See Cell, 2.
   [1913 Webster]

   Note: Of such houses there were two sorts: one where the
         prior was chosen by the inmates, and governed as
         independently as an abbot in an abbey; the other where
         the priory was subordinate to an abbey, and the prior
         was placed or displaced at the will of the abbot.
         [1913 Webster]

   Alien priory, a small religious house dependent on a large
      monastery in some other country.
      [1913 Webster]

   Syn: See Cloister.
        [1913 Webster]

WordNet (r) 3.0 (2006):

priory
    n 1: religious residence in a monastery governed by a prior or a
         convent governed by a prioress