If a place is hilly, it has a lot of hills. The land keeps going up and down; it is not flat. We say a hilly town, a hilly road, hilly countryside. Hilly is milder than mountainous: mountains are bigger, steeper, and often snowy. A hilly park may tire your legs; a mountainous region has real peaks. The ending -y turns the noun hill into an adjective, the same pattern as rocky, icy, or sunny. The usual comparative and superlative are hillier and hilliest, though people also say more hilly in loose talk.

多丘陵的；丘陵起伏的