The Collaborative International Dictionary of English v.0.48:

highfalutin \highfalutin\ highfaluting \highfaluting\
highfalutin' \highfalutin'\adj.
   Affectedly genteel; pretentious; haughty; snobbish. [Written
   also hifalutin.] [informal]

   Syn: grandiose, hifalutin, hoity-toity, la-di-da.
        [WordNet 1.5] highfalutin

The Collaborative International Dictionary of English v.0.48:

highfalutin \high`fa*lu"tin\, highfaluting \high`fa*lu"ting\, n.
   [Perh. a corruption of highflighting.]
   High-flown, bombastic language. [Written also hifalutin.]
   [Jocular, U. S.] --Lowell.
   [1913 Webster]

WordNet (r) 3.0 (2006):

highfalutin
    adj 1: affectedly genteel [syn: grandiose, hifalutin,
           highfalutin, highfaluting, hoity-toity, la-di-da]

Moby Thesaurus II by Grady Ward, 1.0:

94 Moby Thesaurus words for "highfalutin":
   Gongoresque, Johnsonian, affected, ambitious, arrogant, aureate,
   bedizened, big, big-sounding, bombastic, classy, condescending,
   convoluted, declamatory, domineering, elevated, euphuistic,
   extravagant, fancy, flamboyant, flaming, flashy, flaunting, florid,
   flossy, flowery, fulsome, fustian, garish, gassy, gaudy,
   grandiloquent, grandiose, grandisonant, haughty, high,
   high-faluting, high-flowing, high-flown, high-flying, high-headed,
   high-minded, high-nosed, high-sounding, high-swelling, high-toned,
   highfaluting, hoity-toity, inflated, inkhorn, labyrinthine,
   lexiphanic, lexiphanicism, lofty, lurid, magniloquent,
   meretricious, oratorical, orotund, ostentatious, overbearing,
   overdone, overelaborate, overinvolved, overwrought, patronizing,
   pedantic, pompous, pretentious, proud, purse-proud, rant, rhapsody,
   rhetoric, rhetorical, rodomontade, sensational, sensationalistic,
   sententious, showy, sonorous, stilted, stuck-up, superior, swollen,
   tall, tony, toplofty, tortuous, uppish, uppity, upstage, vaunting,
   windy