The Collaborative International Dictionary of English v.0.48:

Fecund \Fec"und\, a. [L. fecundus, from the root of fetus: cf.
   F. f['e]cond. see Fetus.]
   Fruitful in children; prolific. --Graunt.
   [1913 Webster]

WordNet (r) 3.0 (2006):

fecund
    adj 1: capable of producing offspring or vegetation
    2: intellectually productive; "a prolific writer"; "a fecund
       imagination" [syn: fecund, fertile, prolific]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "fecund":
   abundant, blooming, bountiful, breeding, bursting, bursting out,
   conceptive, conceptual, copious, creative, diffuse, diffusive,
   effusive, esemplastic, extravagant, exuberant, fertile,
   flourishing, formless, fructiferous, fruitful, generous, germinal,
   gushing, gushy, ideational, ideative, imaginative, ingenious,
   inspired, inventive, lush, luxuriant, notional, original,
   originative, overflowing, plenteous, plentiful, pleonastic,
   pregnant, prodigal, productive, profuse, profusive, proliferous,
   prolific, propagating, redundant, reiterative, repetitive,
   reproducing, rich, seminal, shaping, spawning, superabundant,
   swarming, tautologous, teeming, thriving, uberous, visioned