The Collaborative International Dictionary of English v.0.48:

Moldy \Mold"y\, Mouldy \Mould"y\, a. [Compar. Moldieror
   Mouldier; superl. Moldiest or Mouldiest.] [From Mold
   the growth of fungi.]
   Overgrown with, or containing, mold; smelling of mold; as,
   moldy cheese or bread.
   [1913 Webster]

WordNet (r) 3.0 (2006):

moldy
    adj 1: covered with or smelling of mold; "moldy bread"; "a moldy
           (or musty) odor" [syn: moldy, mouldy, musty]

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "moldy":
   archaic, bad, bad-smelling, blasted, blighted, blown, bygone,
   crumbling, dated, despoiled, dilapidated, dusty, fecal, fetid,
   flyblown, foul, frowsty, frowsy, frowy, frowzy, fulsome, funky,
   fusty, gamy, gone to seed, graveolent, high, ill-smelling, maggoty,
   malodorous, mephitic, miasmal, miasmic, mildewed, mildewy,
   moldering, moss-grown, moth-eaten, musty, nidorous, noisome,
   noxious, odorous, offensive, old hat, olid, outdated, passe,
   putrid, rancid, rank, ravaged, reasty, reasy, reechy, reeking,
   reeky, repulsive, rococo, rotten, ruined, ruinous, rusty, smellful,
   smelling, smelly, smutted, smutty, stale, stenchy, stinking,
   strong, stuffy, sulfurous, time-scarred, timeworn, vile, weevily,
   worm-eaten, wormy, worn