Synonyms and related words :
big, big-league, big-name, big-time, bigwig, bigwigged, booming, consequential, considerable, deafening, double-barreled, ear-piercing, ear-rending, ear-splitting, forte, fortissimo, full, grand, great, heavyweight, high-powered, important, loud, loud-sounding, loudish, major, material, momentous, name, pealing, piercing, plangent, resounding, ringing, self-important, significant, sonorous, stentoraphonic, stentorian, stentorious, substantial, superior, thunderous, tonitruant, tonitruous, window-rattling, world-shaking