IPA: /ˈhɪliər/
KK: /ˈhɪliər/
Having more hills than something else; used to describe a landscape that is more elevated or uneven.
The region became hillier as we traveled further into the mountains.
Hillier → The word is formed from "hill" (from Old English "hyll", meaning a raised area of land) and the suffix "-ier" (meaning more). Thus, "hillier" describes a landscape that has more hills than another.
Think of a landscape with 'more hills' — 'hill' refers to the raised areas, and '-ier' indicates a greater amount.