'Slyness' definitions:

Definition of 'slyness'

From: WordNet
noun
Shrewdness as demonstrated by being skilled in deception [syn: craft, craftiness, cunning, foxiness, guile, slyness, wiliness]

Definition of 'Slyness'

From: GCIDE
  • Slyness \Sly"ness\, n. The quality or state of being sly. [1913 Webster]