WordNet (r) 3.0 (2006):

bumpy
    adj 1: causing or characterized by jolts and irregular
           movements; "a rough ride" [syn: rough, rocky,
           bumpy, jolty, jolting, jumpy] [ant: smooth]
    2: covered with or full of bumps; "a bumpy country road"

Moby Thesaurus II by Grady Ward, 1.0:

74 Moby Thesaurus words for "bumpy":
   bagging, baggy, ballooning, bellying, billowing, billowy, bloated,
   bosomy, bouncy, broken, bulbose, bulbous, bulging, bumped, bunched,
   bunchy, choppy, coarse, coarse-grained, corrugated, cross-grained,
   distended, grainy, granulated, hillocky, homespun, horripilant,
   hummocky, inequal, irregular, jarring, jerky, jogglety, joggling,
   joggly, jolting, jolty, knobbly, knobby, linsey-woolsey, lumpy,
   moutonnee, pimply, pitted, pneumatic, pocky, potbellied, potholed,
   pouching, rank, ripply, rough, rough-cast, rough-grained,
   rough-hewn, rounded, ruffled, rutted, rutty, shagged, shaggy,
   swelling, textured, uneven, unkempt, unlevel, unpolished,
   unrefined, unsmooth, ununiform, verrucated, verrucose, warty,
   wimpled