The Collaborative International Dictionary of English v.0.48:

Commandery \Com*mand"er*y\, n.; pl. Commanderies. [F.
   commanderie.]
   1. The office or rank of a commander. [Obs.]
      [1913 Webster]

   2. A district or a manor with lands and tenements
      appertaining thereto, under the control of a member of an
      order of knights who was called a commander; -- called
      also a preceptory.
      [1913 Webster]

   3. An assembly or lodge of Knights Templars (so called) among
      the Freemasons. [U. S.]
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   4. A district under the administration of a military
      commander or governor. [R.] --Brougham.
      [1913 Webster]

WordNet (r) 3.0 (2006):

commandery
    n 1: the position or office of commander [syn: commandership,
         commandery]