(すその)

すその
noun
foot of a mountain; base; breadth
geography
1. foot of a mountain, foothills
The broad, gently sloping area at the base of a mountain or volcano.
The foothills of Mount Fuji are vast.
There is a small village at the foot of the mountain.
Cattle were grazing on the grasslands that spread across the foothills.
2. base, breadth, range (figurative)
Used figuratively to describe the broad base or wide reach of something, such as the range of people involved in an industry or the spread of a trend.
This industry has a broad base.
The reach of the gaming industry is expanding.
In a technology field with a wide base, many companies are involved.

Kanji: (すそ) means hem/skirt/bottom edge; () means field/plain. Together they describe the "hem" or bottom edge of a mountain spreading out like fabric.

Common collocations

Note: Also the name of a city (裾野(すその)()) in Shizuoka Prefecture, located at the foot of Mount Fuji.