Source : Webster's Revised Unabridged Dictionary (1913)

Obliqueness \Ob*lique"ness\, n.
   Quality or state of being oblique.

Source : WordNet®

obliqueness
     n 1: the property of being neither parallel nor perpendicular,
          but at a slanting angle
     2: the quality of being oblique and rambling indirectly [syn: {deviousness}]