-ory

from The Century Dictionary.

• Bearing or containing ore: as, ory matters. Also spelled orey.
• A termination of adjectives and nouns of Latin origin, as in auditory, preparatory, etc.

from the GNU version of the Collaborative International Dictionary of English.

• suffix An adjective suffix meaning of or pertaining to, serving for; as in auditory, pertaining to or serving for hearing; prohibitory, amendatory, etc.
• suffix A noun suffix denoting that which pertains to, or serves for; as in ambulatory, that which serves for walking; consistory, factory, etc.