Source : Webster's Revised Unabridged Dictionary (1913)

Iniquitous \In*iq"ui*tous\, a. [From {Iniquity}.]
   Characterized by iniquity; unjust; wicked; as, an iniquitous
   bargain; an iniquitous proceeding.

         Demagogues . . . bribed to this iniquitous service.
                                                  --Burke.

   Syn: Wicked; wrong; unjust; unrighteous; nefarious; criminal.

   Usage: {Iniquitous}, {Wicked}, {Nefarious}. Wicked is the
          generic term. Iniquitous is stronger, denoting a
          violation of the rights of others, usually by fraud or
          circumvention. Nefarious is still stronger, implying a
          breach of the most sacred obligations, and points more
          directly to the intrinsic badness of the deed.

Source : WordNet®

iniquitous
     adj : characterized by iniquity; wicked because it is believed to
           be a sin; "iniquitous deeds"; "he said it was sinful to
           wear lipstick"; "ungodly acts" [syn: {sinful}, {ungodly}]