The Collaborative International Dictionary of English v.0.48:

Impracticability \Im*prac`ti*ca*bil"i*ty\, n.; pl.
   Impracticabilities.
   1. The state or quality of being impracticable;
      infeasibility. --Goldsmith.
      [1913 Webster]

   2. An impracticable thing.
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   3. Intractableness; stubbornness.
      [1913 Webster]