Source : Webster's Revised Unabridged Dictionary (1913)

Insolvable \In*solv"a*ble\, a.
   1. Not solvable; insoluble; admitting no solution or
      explanation; as, an insolvable problem or difficulty. --I.
      Watts.

   2. Incapable of being paid or discharged, as debts.

   3. Not capable of being loosed or disentangled; inextricable.
      ``Bands insolvable.'' --Pope.

Source : WordNet®

insolvable
     adj : not easily solved; "an apparantly insolvable problem";
           "public finance...had long presented problems
           unsolvable or at least unsolved"- C.L.Jones [syn: {unsoluble},
            {unsolvable}, {unresolvable}]