The Collaborative International Dictionary of English v.0.48:

Opulent \Op"u*lent\, a. [L. opulens, opulentus, fr. ops, opis,
   power, wealth, riches, perh. akin to E. apt: cf. F. opulent.
   Cf. Copious, Couple, Office.]
   Having a large estate or property; wealthy; rich; affluent;
   as, an opulent city; an opulent citizen. -- Op"u*lent*ly,
   adv.
   [1913 Webster]

         I will piece
         Her opulent throne with kingdoms.        --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

opulent
    adj 1: rich and superior in quality; "a princely sum"; "gilded
           dining rooms" [syn: deluxe, gilded, grand,
           luxurious, opulent, princely, sumptuous]

Moby Thesaurus II by Grady Ward, 1.0:

98 Moby Thesaurus words for "opulent":
   abounding, abounding in riches, abundant, affluent, all-sufficing,
   ample, aplenty, big-rich, bottomless, bounteous, bountiful,
   comfortable, copious, deluxe, diffuse, disgustingly rich, effuse,
   epidemic, exhaustless, extravagant, exuberant, fat, fertile, flush,
   frightfully rich, full, galore, generous, in clover, in funds,
   in plenty, in quantity, in the money, in velvet, independent,
   independently rich, independently wealthy, inexhaustible, lavish,
   liberal, loaded, luscious, lush, luxuriant, luxurious,
   made of money, many, maximal, moneyed, much, numerous,
   on Easy Street, on velvet, oofy, ostentatious, overflowing,
   palatial, plenitudinous, plenteous, plentiful, plenty, plush,
   pretentious, prevailing, prevalent, prodigal, productive, profuse,
   profusive, prolific, prosperous, provided for, rampant, replete,
   rich, rich as Croesus, rife, riotous, rolling in money,
   running over, showy, sumptuous, superabundant, swank, teeming,
   wallowing in wealth, warm, wealthy, well provided for, well-fixed,
   well-found, well-furnished, well-heeled, well-off, well-provided,
   well-stocked, well-to-do, wholesale