The Collaborative International Dictionary of English v.0.48:

Bombastic \Bom*bas"tic\ (b[o^]m*b[.a]s"t[i^]k or
   b[u^]m*b[.a]s"t[i^]k), Bombastical \Bom*bas"tic*al\, a.
   Characterized by bombast; high-sounding; inflated. --
   Bom*bas"tic*al*ly, adv.
   [1913 Webster]

         A theatrical, bombastic, windy phraseology. --Burke.
   [1913 Webster]

   Syn: Turgid; tumid; pompous; grandiloquent.
        [1913 Webster]

WordNet (r) 3.0 (2006):

bombastic
    adj 1: ostentatiously lofty in style; "a man given to large
           talk"; "tumid political prose" [syn: bombastic,
           declamatory, large, orotund, tumid, turgid]

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "bombastic":
   Latinate, aureate, awkward, big, bloated, cramped, cumbrous,
   declamatory, elephantine, euphuistic, extravagant, flatulent,
   flowery, forced, formal, fustian, gassy, grandiloquent, grandiose,
   guinde, halting, heavy, high-flown, high-swelling, highfalutin,
   highfaluting, inflated, inkhorn, labored, leaden, lumbering,
   magniloquent, mouthy, overblown, pompous, ponderous, pontifical,
   pretentious, self-important, sesquipedalian, solemn, sonorous,
   stiff, stilted, stuffy, swollen, tall, tumescent, tumid,
   turgescent, turgid, unwieldy, windy