The Collaborative International Dictionary of English v.0.48:
Hilly \Hill"y\, a. 1. Abounding with hills; uneven in surface; as, a hilly country. "Hilly steep." --Dryden. [1913 Webster] 2. Lofty; as, hilly empire. [Obs.] --Beau. & Fl. [1913 Webster]WordNet (r) 3.0 (2006):
hilly adj 1: having hills and crags; "hilly terrain" [syn: cragged, craggy, hilly, mountainous]