The Collaborative International Dictionary of English v.0.48:

Clamorous \Clam"or*ous\, a. [LL. clamorosus, for L. Clamosus:
   cf. OF. clamoreux.]
   Speaking and repeating loud words; full of clamor; calling or
   demanding loudly or urgently; vociferous; noisy; bawling;
   loud; turbulent. "My young ones were clamorous for a
   morning's excursion." --Southey. -- Clam"or*ous*ly, adv. --
   Clam"or*ous*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

clamorous
    adj 1: conspicuously and offensively loud; given to vehement
           outcry; "blatant radios"; "a clamorous uproar"; "strident
           demands"; "a vociferous mob" [syn: blatant, clamant,
           clamorous, strident, vociferous]

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "clamorous":
   acute, articulate, bawling, begging, blaring, blatant, blatting,
   blustering, boanergean, boisterous, brassy, brawling, brazen,
   burning, clamant, clamoursome, clanging, clangorous, clattery,
   compelling, critical, crucial, crying, demanding, dire, draining,
   eloquent, exacting, exigent, exorbitant, extortionate, grasping,
   high-pressure, high-priority, imperative, imperious, imploring,
   importunate, insistent, instant, loud, loudmouthed, mafficking,
   multivocal, noiseful, noisy, obstreperous, openmouthed, persistent,
   pertinacious, pivotal, pressing, rackety, rip-roaring, rowdy,
   screaming, shouting, strepitant, strepitous, strident, taxing,
   tempestuous, tumultuous, turbulent, uproarious, urgent, vocal,
   vociferant, vociferating, vociferous, voluble, yammering, yapping,
   yelling, yelping