The Collaborative International Dictionary of English v.0.48:

Recidivist \Re*cid"i*vist\ (r[-e]*s[i^]d"[i^]*v[i^]st), n.
   One who is recidivous or is characterized by recidivism; an
   incorrigible criminal. -- Re*cid`i*vis"tic
   (r[-e]*s[i^]d`[i^]*v[i^]s"t[i^]k), a.
   [Webster 1913 Suppl.]

         The criminal by passion never becomes a recidivist, it
         is the social, not the antisocial, instincts that are
         strong within him, his crime is a solitary event in his
         life.                                    --Havelock
                                                  Ellis.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

recidivist
    n 1: someone who is repeatedly arrested for criminal behavior
         (especially for the same criminal behavior) [syn:
         recidivist, repeater, habitual criminal]
    2: someone who lapses into previous undesirable patterns of
       behavior [syn: recidivist, backslider, reversionist]

Moby Thesaurus II by Grady Ward, 1.0:

109 Moby Thesaurus words for "recidivist":
   Adamic, Sabbath-breaker, apostate, atavistic, atheist, atheistic,
   backslider, backsliding, bad egg, bad lot, black sheep, blasphemer,
   blasphemous, bolter, carnal, collaborationist, collaborator,
   convert, defector, degenerate, deserter, erring, fallen,
   fallen angel, fallen from grace, fifth columnist, fleshly, frail,
   impious, impure, infirm, irreligious, irreverent, lapsed, lecher,
   lost lamb, lost sheep, lost soul, miscreant, mugwump,
   of easy virtue, peccable, pervert, pimp, postlapsarian, prodigal,
   prodigal son, profanatory, profane, profligate, proselyte,
   quisling, reactionary, recessive, recidivistic, recidivous,
   recreant, regressive, renegade, renegado, renegate, repeater,
   reprobate, retrograde, retrogressive, retrorse, retroverse,
   returnable, returnee, reversible, reversional, reversionary,
   reversioner, reversionist, revertible, revulsionary, runagate,
   sacrilegious, sacrilegist, scapegrace, schismatic, seceder,
   secessionist, separatist, sorry lot, strikebreaker, tergiversant,
   tergiversator, traitor, trollop, turnabout, turncoat, turntail,
   two-time loser, unangelic, unbeliever, unchaste, unclean,
   undutiful, ungodly, ungood, unrighteous, unsaintly, unvirtuous,
   virtueless, wanton, wayward, weak, whore