The Collaborative International Dictionary of English v.0.48:

Inveteracy \In*vet"er*a*cy\, n. [From Inveterate.]
   [1913 Webster]
   1. Firm establishment by long continuance; firmness or
      deep-rooted obstinacy of any quality or state acquired by
      time; as, the inveteracy of custom, habit, or disease; --
      usually in a bad sense; as, the inveteracy of prejudice or
      of error.
      [1913 Webster]

            An inveteracy of evil habits that will prompt him to
            contract more.                        --A. Tucker.
      [1913 Webster]

   2. Malignity; spitefulness; virulency.
      [1913 Webster]

            The rancor of pamphlets, the inveteracy of epigrams,
            and the mortification of lampoons.    --Guardian.
      [1913 Webster]