The Collaborative International Dictionary of English v.0.48:

Outrageous \Out*ra"geous\ (out*r[=a]"j[u^]s), a. [OF. outrageus,
   F. outrageux. See Outrage, n.]
   Of the nature of an outrage; exceeding the limits of right,
   reason, or decency; such as to cause outrage; involving or
   doing an outrage; furious; violent; atrocious. "Outrageous
   weeping." --Chaucer. "The most outrageous villainies." --Sir
   P. Sidney. "The vile, outrageous crimes." --Shak. "Outrageous
   panegyric." --Dryden.
   [1913 Webster]

   Syn: Violent; furious; exorbitant; excessive; atrocious;
        monstrous; wanton; nefarious; heinous.
        [1913 Webster] -- Out*ra"geous*ly
        (out*r[=a]"j[u^]s*l[y^]), adv. -- Out*ra"geous*ness,
        n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

outrageous
    adj 1: grossly offensive to decency or morality; causing horror;
           "subjected to outrageous cruelty"; "a hideous pattern of
           injustice"; "horrific conditions in the mining industry"
           [syn: hideous, horrid, horrific, outrageous]
    2: greatly exceeding bounds of reason or moderation; "exorbitant
       rent"; "extortionate prices"; "spends an outrageous amount on
       entertainment"; "usurious interest rate"; "unconscionable
       spending" [syn: exorbitant, extortionate, outrageous,
       steep, unconscionable, usurious]

Moby Thesaurus II by Grady Ward, 1.0:

249 Moby Thesaurus words for "outrageous":
   Fescennine, a bit much, abandoned, abominable, absurd, abusive,
   acute, appalling, arrant, atrocious, awful, backhand, backhanded,
   barbaric, barbarous, base, beastly, beneath contempt, beneath one,
   beyond belief, bizarre, blameworthy, boundless, brutal, calumnious,
   cheap, cockamamie, contemptible, contumelious, crazy, cruel,
   crying, cutthroat, cutting, debasing, debauched, degenerate,
   degrading, demeaning, deplorable, depraved, desperate, despicable,
   detestable, dire, dirty, disgraceful, disgusting, dissipated,
   dissolute, drastic, dreadful, egregious, embarrassing, enormous,
   evil, exacting, exaggerated, excessive, execrable, exorbitant,
   explicit, extortionate, extravagant, extreme, fabulous, fancy,
   fantastic, fetid, fierce, filthy, flagrant, foolish, foul,
   foul-mouthed, fulsome, furious, ghastly, gigantic, gluttonous,
   gouging, great, grievous, grisly, gross, grossly overpriced,
   grotesque, gutter, hateful, heinous, hideous, high, high-flown,
   horrendous, horrible, horrid, humiliating, humiliative, hyperbolic,
   hypertrophied, immoderate, immoral, impossible, improper,
   inappropriate, incontinent, incredible, indecent, indecorous,
   indelicate, infamous, inflationary, infra dig, infra indignitatem,
   inhuman, iniquitous, inordinate, insolent, insulting, intemperate,
   intense, intolerable, keen, lamentable, laughable, left-handed,
   lewd, loathsome, lousy, ludicrous, monstrous, nasty, naughty,
   nauseating, nauseous, nefarious, noisome, nonmeritorious,
   nonsensical, not coming, not outstanding, notorious, objectionable,
   obnoxious, obscene, odious, offensive, opprobrious, out of bounds,
   out of sight, outre, overbig, overdeveloped, overgreat, overgrown,
   overlarge, overmuch, overpriced, overweening, perverted, piercing,
   pitiable, pitiful, poppycockish, pornographic, preposterous,
   profane, profligate, prohibitive, rank, regrettable, repellent,
   reprehensible, repugnant, repulsive, revolting, ridiculous,
   rigorous, rotten, rough, rude, sad, salacious, scandalous,
   scatological, schlock, scurrile, scurrilous, scurvy, severe,
   shabby, shameful, sharp, shocking, shoddy, skyrocketing, smutty,
   sordid, sorry, spiraling, splitting, squalid, steep, stiff,
   terrible, too bad, too much, tough, unbecoming, unbridled,
   unchristian, uncivilized, unclean, unconscionable, undeserved,
   undeserving, undue, unearned, unentitled, ungodly, unholy,
   unjustified, unmerited, unmeriting, unowed, unowing, unreasonable,
   unrestrained, unseemly, unspeakable, unthinkable, unwarranted,
   unworthy, unworthy of one, usurious, vehement, venomous, vicious,
   vile, villainous, violent, virulent, weird, wicked, wild, woeful,
   worst, worthless, wretched