The Collaborative International Dictionary of English v.0.48:

Transgressively \Trans*gress"ive*ly\, adv.
   [1913 Webster]

         Adam, perhaps, . . . from the transgressive infirmities
         of himself, might have erred alone.      --Sir T.
                                                  Browne.
   [1913 Webster] Transgressor \Trans*gress"or\, n. [L.: cf. F.
   transgresseur.]
   One who transgresses; one who breaks a law, or violates a
   command; one who violates any known rule or principle of
   rectitude; a sinner.
   [1913 Webster]

         The way of transgressors is hard.        --Prov. xiii.
                                                  15.
   [1913 Webster]

WordNet (r) 3.0 (2006):

transgressor
    n 1: someone who transgresses; someone who violates a law or
         command; "the way of transgressors is hard"

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "transgressor":
   bad person, criminal, crook, culprit, deceiver, delinquent,
   evil man, evil person, evildoer, felon, gangster, lawbreaker,
   malefactor, malevolent, malfeasant, malfeasor, miscreant,
   misdemeanant, misdemeanist, misfeasor, mobster, offender, outlaw,
   public enemy, racketeer, sinner, thief, trespasser, villain,
   worker of ill, wrongdoer