火か山ざん岩がん尖せん

noun

volcanic spine

A geological term for a steep-sided, pillar-like protrusion of solidified lava or volcanic rock, often formed by erosion of surrounding material.

• 火か山ざん岩がん尖せんは、火か山ざん活かつ動どうの後あとに残のこる鋭するどい岩いわの突とっ起きである。

  A volcanic spine is a sharp rock protrusion left after volcanic activity.