Nefarious

nefarious
    adj 1: extremely wicked; "nefarious schemes"; "a villainous
           plot"; "a villainous band of thieves" [syn: {nefarious},
           {villainous}]
    

Nefarious \Ne*fa"ri*ous\, a. [L. nefarius, fr. nefas crime,
   wrong; ne not + fas divine law; akin to fari to speak. See
   {No}, adv., and {Fate}.]
   Wicked in the extreme; abominable; iniquitous; atrociously
   villainous; execrable; detestably vile.
   [1913 Webster]

   Syn: Iniquitous; detestable; horrible; heinious; atrocious;
        infamous; impious. See {Iniquitous}.
        [1913 Webster] -- {Ne*fa"ri*ous*ly}, adv. --
        {Ne*fa"ri*ous*ness}, n.
        [1913 Webster]
    

125 Moby Thesaurus words for "nefarious":
      abject, abominable, arrant, atrocious, awful, bad, base, beastly,
      beggarly, beneath contempt, black, blamable, blameworthy, brutal,
      cheesy, contemptible, corrupt, criminal, crummy, damnable, dark,
      debased, degenerate, degraded, deplorable, depraved, despicable,
      detestable, dire, dirty, disgraceful, disgusting, dreadful,
      egregious, enormous, evil, execrable, fetid, filthy, flagitious,
      flagrant, foul, fulsome, glaring, grave, grievous, gross, hateful,
      heinous, horrible, horrid, improper, infamous, iniquitous, knavish,
      lamentable, little, loathsome, lousy, low, low-down, lumpen, mangy,
      mean, measly, miscreant, miserable, monstrous, nasty, naughty,
      noisome, notorious, obnoxious, odious, offensive, outrageous,
      paltry, peccant, perverse, petty, pitiable, pitiful, poky, poor,
      putrid, rank, regrettable, reprehensible, reprobate, reptilian,
      repulsive, rotten, sad, scabby, scandalous, schlock, scrubby,
      scruffy, scummy, scurvy, shabby, shameful, shocking, shoddy,
      sinful, small, sordid, squalid, terrible, too bad, unclean,
      unforgivable, unmentionable, unpardonable, unspeakable, unworthy,
      vicious, vile, villainous, wicked, woeful, worst, worthless,
      wretched, wrong