The Collaborative International Dictionary of English v.0.48:

Fertility \Fer*til"i*ty\, n. [L. fertilitas: cf. F.
   fertilit['e].]
   The state or quality of being fertile or fruitful;
   fruitfulness; productiveness; fecundity; richness; abundance
   of resources; fertile invention; quickness; readiness; as,
   the fertility of soil, or of imagination. "fertility of
   resource." --E. Everett.
   [1913 Webster]

         And all her husbandry doth lie on heaps
         Corrupting in its own fertility.         --Shak.
   [1913 Webster]

         Thy very weeds are beautiful; thy waste
         More rich than other climes' fertility.  --Byron.
   [1913 Webster]

WordNet (r) 3.0 (2006):

fertility
    n 1: the ratio of live births in an area to the population of
         that area; expressed per 1000 population per year [syn:
         birthrate, birth rate, fertility, fertility rate,
         natality]
    2: the state of being fertile; capable of producing offspring
       [syn: fertility, fecundity] [ant: infertility,
       sterility]
    3: the property of producing abundantly and sustaining vigorous
       and luxuriant growth; "he praised the richness of the soil";
       "weeds lovely in their rankness" [syn: richness,
       rankness, prolificacy, fertility]

Moby Thesaurus II by Grady Ward, 1.0:

113 Moby Thesaurus words for "fertility":
   abundance, affluence, ample sufficiency, ampleness, amplitude,
   avalanche, bonanza, bountifulness, bountiousness, bumper crop,
   cloud of words, copiousness, creativeness, creativity, diffuseness,
   diffusion, diffusiveness, effusion, effusiveness, extravagance,
   exuberance, fecundity, fertile mind, flood, flow, fluency, foison,
   formlessness, fructiferousness, fruitfulness, full measure,
   fullness, generosity, generousness, great abundance, great plenty,
   gush, gushing, ingenuity, invention, inventiveness, landslide,
   lavishness, liberality, liberalness, logorrhea, lots, lushness,
   luxuriance, macrology, maximum, more than enough, much, myriad,
   myriads, numerousness, opulence, opulency, originality, outpour,
   outpouring, overflow, palilogy, plenitude, plenteousness,
   plentifulness, plenty, pleonasm, pregnancy, pregnant imagination,
   prevalence, procreativeness, prodigality, productive capacity,
   productiveness, productivity, profuseness, profusion, prolificacy,
   prolificity, quantities, rampancy, rankness, redundancy,
   reiteration, reiterativeness, repetition for effect,
   repetitiveness, repleteness, repletion, resourcefulness,
   rich harvest, rich vein, richness, riot, riotousness, scads,
   shower, spate, stream, substantiality, substantialness,
   superabundance, superfluity, superflux, swarmingness,
   talkativeness, tautology, teeming imagination, teeming womb,
   teemingness, tirade, wealth