Source : Webster's Revised Unabridged Dictionary (1913)

Incumbency \In*cum"ben*cy\, n.; pl. {Incumbencies}. [From
   {Incumbent}.]
   1. The state of being incumbent; a lying or resting on
      something.

   2. That which is physically incumbent; that which lies as a
      burden; a weight. --Evelyn.

   3. That which is morally incumbent, or is imposed, as a rule,
      a duty, obligation, or responsibility. ``The incumbencies
      of a family.'' --Donne.

   4. The state of holding a benefice; the full possession and
      exercise of any office.

            These fines are only to be paid to the bishop during
            his incumbency.                       --Swift.