The Collaborative International Dictionary of English v.0.48:

Uproarious \Up*roar"i*ous\, a.
   Making, or accompanied by, uproar, or noise and tumult; as,
   uproarious merriment.
   [1913 Webster] -- Up*roar"i*ous*ly, adv. --
   Up*roar"i*ous*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

uproarious
    adj 1: uncontrollably noisy [syn: rackety, rip-roaring,
           uproarious]
    2: marked by or causing boisterous merriment or convulsive
       laughter; "hilarious broad comedy"; "a screaming farce";
       "uproarious stories" [syn: hilarious, screaming(a),
       uproarious]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "uproarious":
   anarchic, angry, blaring, blatant, blatting, blustering,
   blusterous, blustery, boisterous, brassy, brawling, brazen,
   chaotic, clamant, clamorous, clamoursome, clanging, clangorous,
   clattery, deafening, disorderly, excited, frantic, frenzied,
   furious, hellish, hilarious, hysterical, infuriate, insensate,
   killing, mad, mafficking, mindless, noiseful, noisy, obstreperous,
   orgasmic, orgastic, pandemoniac, rackety, raging, ravening, raving,
   riotous, rip-roaring, rowdy, sonorous, storming, stormy,
   strepitant, strepitous, tempestuous, troublous, tumultuous,
   turbulent, vociferous, wild