The Collaborative International Dictionary of English v.0.48:

Blameworthy \Blame"wor`thy\, a.
   Deserving blame; culpable; reprehensible. --
   Blame"wor`thi*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

blameworthy
    adj 1: deserving blame or censure as being wrong or evil or
           injurious; "blameworthy if not criminal behavior";
           "censurable misconduct"; "culpable negligence" [syn:
           blameworthy, blamable, blameable, blameful,
           censurable, culpable]

Moby Thesaurus II by Grady Ward, 1.0:

119 Moby Thesaurus words for "blameworthy":
   abominable, accusable, amiss, arraignable, arrant, at fault,
   atrocious, awful, bad, base, beastly, beneath contempt, black,
   blamable, blameful, brutal, censurable, chargeable, contemptible,
   criminal, culpable, damnable, dark, delinquent, deplorable,
   despicable, detestable, dire, disgraceful, disgusting, dreadful,
   egregious, enormous, evil, execrable, faultful, fetid, filthy,
   flagitious, flagrant, foolish, foul, fulsome, grievous, gross,
   guilty, hateful, heinous, horrible, horrid, illaudable,
   impeachable, improper, imputable, indictable, infamous, iniquitous,
   irresponsible, knavish, lamentable, loathsome, lousy, low,
   monstrous, nasty, naughty, nefarious, noisome, notorious,
   obnoxious, odious, offensive, open to criticism, outrageous,
   peccant, pitiable, pitiful, punishable, rank, reckless,
   regrettable, reprehensible, reproachable, reprobate, reprovable,
   repulsive, rotten, sad, scandalous, schlock, scurvy, shabby,
   shameful, shocking, shoddy, sinful, sordid, squalid, terrible,
   to blame, too bad, unclean, uncommendable, unforgivable, unholy,
   unpardonable, unpraiseworthy, unpretty, unspeakable, unworthy,
   vicious, vile, villainous, wicked, woeful, worst, worthless,
   wretched, wrong