The Collaborative International Dictionary of English v.0.48:

Superabundant \Su`per*a*bun"dant\, a. [L. superabundans, p. pr.
   of superabundare. See Superabound.]
   Abounding to excess; being more than is sufficient;
   redundant; as, superabundant zeal. -- Su`per*a*bun"dant*ly,
   adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

superabundant
    adj 1: most excessively abundant

Moby Thesaurus II by Grady Ward, 1.0:

124 Moby Thesaurus words for "superabundant":
   abounding, abundant, affluent, alive with, all-sufficing, ample,
   aplenty, blooming, bottomless, bounteous, bountiful, bristling,
   bursting, bursting out, copious, countless, crawling, creative,
   crowded, crowding, diffuse, diffusive, effuse, effusive, epidemic,
   excess, excessive, exhaustless, extravagant, exuberant, fat,
   fecund, fertile, flourishing, flush, formless, fructiferous,
   fruitful, full, galore, generous, gushing, gushy, in plenty,
   in profusion, in quantity, inexhaustible, jam-packed, jammed,
   lavish, liberal, lush, luxuriant, many, maximal, much,
   multitudinous, numerous, opulent, overabundant, overbounteous,
   overcopious, overexuberant, overflowing, overgenerous, overlavish,
   overliberal, overluxuriant, overmuch, overnumerous, overplenteous,
   overplentiful, overplenty, overpopulated, overpopulous,
   overprolific, packed, plenitudinous, plenteous, plentiful, plenty,
   pleonastic, plethoric, populous, pregnant, prevailing, prevalent,
   prodigal, productive, profuse, profusive, proliferating,
   proliferous, prolific, pullulating, rampant, redundant,
   reiterative, repetitive, replete, rich, rife, riotous,
   running over, seminal, studded, surplus, swarming, tautologous,
   teeming, thick, thick as hail, thick with, thick-coming, thriving,
   thronged, thronging, uberous, wealthy, well-found, well-furnished,
   well-provided, well-stocked, wholesale