Source : Webster's Revised Unabridged Dictionary (1913)

Appetency \Ap"pe*ten*cy\, n.; pl. {Appetencies}. [L. appetentia,
   fr. appetere to strive after, long for. See {Appetite}.]
   1. Fixed and strong desire; esp. natural desire; a craving;
      an eager appetite.

            They had a strong appetency for reading. --Merivale.

   2. Specifically: An instinctive inclination or propensity in
      animals to perform certain actions, as in the young to
      suck, in aquatic fowls to enter into water and to swim;
      the tendency of an organized body to seek what satisfies
      the wants of its organism.

            These lacteals have mouths, and by animal selection
            or appetency the absorb such part of the fluid as is
            agreeable to their palate.            --E. Darwin.

   3. Natural tendency; affinity; attraction; -- used of
      inanimate objects.

Source : WordNet®

appetency
     n : a feeling of craving something; "an appetite for life"; "the
         object of life is to satisfy as many appetencies as
         possible"- Granville Hicks [syn: {appetite}, {appetence}]