Source : Webster's Revised Unabridged Dictionary (1913)

Tractable \Tract"a*ble\, a. [L. tractabilis, fr, tractare to
   draw violently, to handle, treat. See {Treat}, v. t.]
   1. Capable of being easily led, taught, or managed; docile;
      manageable; governable; as, tractable children; a
      tractable learner.

            I shall find them tractable enough.   --Shak.

   2. Capable of being handled; palpable; practicable; feasible;
      as, tractable measures. [Obs.] --Holder.
      --{Tract"a*ble*ness}, n. -- {Tract"a/bly}, adv.

Source : WordNet®

tractableness
     n : the trait of being easily persuaded [syn: {tractability}, {flexibility}]
         [ant: {intractability}]