The Collaborative International Dictionary of English v.0.48:

Deceitfulness \De*ceit"ful*ness\, n.
   1. The disposition to deceive; as, a man's deceitfulness may
      be habitual.
      [1913 Webster]

   2. The quality of being deceitful; as, the deceitfulness of a
      man's practices.
      [1913 Webster]

   3. Tendency to mislead or deceive. "The deceitfulness of
      riches." --Matt. xiii. 22.
      [1913 Webster]

WordNet (r) 3.0 (2006):

deceitfulness
    n 1: the quality of being crafty [syn: craftiness,
         deceitfulness, guile]