The Collaborative International Dictionary of English v.0.48:

Usurious \U*su"ri*ous\ (?; 277), a. [From Usury.]
   [1913 Webster]
   1. Practicing usury; taking illegal or exorbitant interest
      for the use of money; as, a usurious person.
      [1913 Webster]

   2. Partaking of usury; containing or involving usury; as, a
      usurious contract.
      [1913 Webster] -- U*su"ri*ous*ly, adv. --
      U*su"ri*ous*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

usuriously
    adv 1: to an exorbitant degree; "prices are exorbitantly high in
           the capital" [syn: exorbitantly, extortionately,
           usuriously]