Source : Webster's Revised Unabridged Dictionary (1913)

Abstrusity \Ab*stru"si*ty\, n.
   Abstruseness; that which is abstruse. [R.] --Sir T. Browne.

Source : WordNet®

abstrusity
     n : wisdom that is recondite and abstruse and profound; "the
         anthropologist was impressed by the reconditeness of the
         native proverbs" [syn: {reconditeness}, {abstruseness}, {profoundness},
          {profundity}]