The Collaborative International Dictionary of English v.0.48:

Punitive \Pu"ni*tive\, a.
   Of or pertaining to punishment; involving, awarding, or
   inflicting punishment; as, punitive law or justice.
   [1913 Webster]

         If death be punitive, so, likewise, is the necessity
         imposed upon man of toiling for his subsistence. -- I.
                                                  Taylor.
   [1913 Webster]

         We shall dread a blow from the punitive hand.
                                                  --Bagehot.
   [1913 Webster]

WordNet (r) 3.0 (2006):

punitive
    adj 1: inflicting punishment; "punitive justice"; "punitive
           damages" [syn: punitive, punitory] [ant:
           rehabilitative]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "punitive":
   avenging, castigating, castigatory, chastening, chastising,
   compensatory, correctional, corrective, disciplinary, grudgeful,
   grueling, implacable, inflictive, irreconcilable, penal,
   penological, punishing, punitory, rancorous, reciprocal,
   recompensing, recompensive, reparative, restitutive, retaliative,
   retaliatory, retributive, retributory, revanchist, revengeful,
   unappeasable, vengeful, vindicatory, vindictive