The Collaborative International Dictionary of English v.0.48:

Nouveau riche \Nou`veau" riche"\, m., Nouvelle riche \Nou`velle"
riche"\, f.; pl. m. Noveaux riches, f. Nouvelles riches.
   [F.]
   A person newly rich. Contrasted with old money.
   [Webster 1913 Suppl. +PJC]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "nouveau riche":
   Babbitt, Philistine, Young Turk, adventurer, arriviste, boor,
   bounder, bourgeois, bourgeois gentilhomme, bright young man, cad,
   churl, clown, comer, epicier, fledgling, groundling, guttersnipe,
   hooligan, ill-bred fellow, looby, lout, low fellow, modern,
   modern generation, modern man, modernist, modernizer, mucker,
   mushroom, name-dropper, neologism, neologist, neology, neonate,
   neoteric, neoterism, neoterist, new generation, new man,
   newly-rich, nouveau roturier, novus homo, parvenu, peasant,
   pig in clover, ribald, rising generation, roturier, rough,
   roughneck, rowdy, ruffian, social climber, sprout, status seeker,
   stripling, tufthunter, upstart, vulgarian, vulgarist,
   would-be gentleman, yokel