adjective, hill·i·er, hill·i·est.

full of hills; having many hills; hilly country.
resembling a hill; elevated; steep.

Origin of hilly

1350–1400; Middle English; Old English hyllīc. See hill, -y1
Related formshill·i·ness, nounun·hill·y, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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Contemporary Examples of hilly

Historical Examples of hilly

Word Origin and History for hilly

late 14c., from hill + -y (2).

Online Etymology Dictionary, © 2010 Douglas Harper