Source : Webster's Revised Unabridged Dictionary (1913)

Knottiness \Knot"ti*ness\, n. [From {Knotty}.]
   1. The quality or state of being knotty or full of knots.

   2. Difficulty of solution; intricacy; complication. ``
      Knottiness of his style.'' --Hare.

Source : WordNet®

knottiness
     n : puzzling complexity [syn: {complicatedness}, {complication}]