The Collaborative International Dictionary of English v.0.48:

Pravity \Prav"i*ty\, n. [L. pravitas, from pravus crooked,
   perverse.]
   Deterioration; degeneracy; corruption; especially, moral
   crookedness; moral perversion; perverseness; depravity; as,
   the pravity of human nature. "The pravity of the will."
   --South.
   [1913 Webster]