Source : Webster's Revised Unabridged Dictionary (1913)

Practicability \Prac"ti*ca*bil"i*ty\, n.
   The quality or state of being practicable; practicableness;
   feasibility. ``The practicability of such a project.''
   --Stewart.

Source : WordNet®

practicability
     n : the quality of being usable [syn: {practicableness}] [ant: {impracticability},
          {impracticability}]