Source : Webster's Revised Unabridged Dictionary (1913)

Hilly \Hill"y\, a.
   1. Abounding with hills; uneven in surface; as, a hilly
      country. ``Hilly steep.'' --Dryden.

   2. Lofty; as, hilly empire. [Obs.] --Beau. & Fl.

Source : WordNet®

hilly
     adj : having hills and crags; "hilly terrain" [syn: {cragged}, {craggy},
            {mountainous}]