Source : Webster's Revised Unabridged Dictionary (1913)

Ostiary \Os"ti*a*ry\, n.; pl. {-ries}. [L. ostium door,
   entrance. See {Usher}.]
   1. The mouth of a river; an estuary. [R.] --Sir T. Browne.

   2. One who keeps the door, especially the door of a church; a
      porter. --N. Bacon.

Source : WordNet®

ostiary
     n 1: the lowest of the minor Holy Orders in the unreformed
          Western Church but now suppressed by the Roman Catholic
          Church [syn: {doorkeeper}, {ostiarius}]
     2: someone who guards an entrance [syn: {doorkeeper}, {doorman},
         {door guard}, {hall porter}, {porter}, {gatekeeper}]