noun
mountainous region; mountain area
Refers to an area or region located in the mountains, often used in geographical or administrative contexts.
山間部では冬になると雪が深く積もる。
In mountainous regions, snow piles up deep in winter.
その村は山間部にあるため、交通の便が悪い。
Because the village is in a mountainous area, access is poor.
Compound of 山 (mountain), 間 (interval, among), and 部 (part, section), literally 'the part among mountains'.