The Collaborative International Dictionary of English v.0.48:

Scandalous \Scan"dal*ous\, a. [Cf. F. scandaleux.]
   1. Giving offense to the conscience or moral feelings;
      exciting reprobation; calling out condemnation.
      [1913 Webster]

            Nothing scandalous or offensive unto any. --Hooker.
      [1913 Webster]

   2. Disgraceful to reputation; bringing shame or infamy;
      opprobrious; as, a scandalous crime or vice.
      [1913 Webster]

   3. Defamatory; libelous; as, a scandalous story.
      [1913 Webster]

WordNet (r) 3.0 (2006):

scandalous
    adj 1: giving offense to moral sensibilities and injurious to
           reputation; "scandalous behavior"; "the wicked rascally
           shameful conduct of the bankrupt"- Thackeray; "the most
           shocking book of its time" [syn: disgraceful,
           scandalous, shameful, shocking]

Moby Thesaurus II by Grady Ward, 1.0:

179 Moby Thesaurus words for "scandalous":
   aberrant, abnormal, abominable, abusive, arrant, atrocious, awful,
   back-biting, backbiting, bad, base, beastly, belittling,
   beneath contempt, beneath one, bitchy, black, blamable,
   blameworthy, brutal, calumniatory, calumnious, catty, censorious,
   cheap, contemptible, contemptuous, contumelious, criminal, crying,
   damnable, dark, debasing, defamatory, degrading, delinquent,
   demeaning, deplorable, deprecatory, depreciative, depreciatory,
   derisive, derisory, derogative, derogatory, desperate, despicable,
   detestable, detracting, detractory, deviant, dire, disgraceful,
   disgusting, dishonorable, disparaging, disreputable, dreadful,
   egregious, enormous, evil, execrable, fetid, filthy, flagitious,
   flagrant, foul, fulsome, grievous, gross, gutter, hardly the thing,
   hateful, heinous, horrible, horrid, humiliating, humiliative,
   ignominious, illegal, immodest, immoral, improper, inappropriate,
   incorrect, indecent, indecorous, infamous, infra dig,
   infra indignitatem, iniquitous, injurious, knavish, lamentable,
   lascivious, lecherous, lewd, libelous, licentious, loathsome,
   lousy, low, lustful, maligning, minimizing, monstrous, nasty,
   naughty, nefarious, noisome, not done, not the thing, notorious,
   obnoxious, odious, off-base, off-color, offensive, opprobrious,
   out-of-line, outrageous, peccant, pejorative, pitiable, pitiful,
   profligate, rank, regrettable, reprehensible, reprobate, repulsive,
   ridiculing, rotten, sacrilegious, sad, schlock, scurrile,
   scurrilous, scurvy, shabby, shameful, shameless, shocking, shoddy,
   sinful, slanderous, slighting, sordid, sorry, squalid, taboo,
   terrible, too bad, unbecoming, unclean, undue, unfit, unfitting,
   unforgivable, unlawful, unmentionable, unpardonable, unrighteous,
   unseemly, unspeakable, unsuitable, unworthy, unworthy of one,
   vicious, vile, vilifying, villainous, wicked, woeful, worst,
   worthless, wretched, wrong, wrongful