subterranean
a dud
EROPSHIN
A dormant volcano is a volcano that is "sleeping," for lack of a better term. It is a volcano that is not currently active.
aquifer
Catacomb
dungens
vulcanologist which is a speciality of geology
A Den. Cave. Underground lair
The matter thrown out of a volcano while it is erupting is called lava, and it consists of melted rock matter. Before erupting, the lava moves underground towards the opening of the volcano. When it is underground like this, it is called magma.
Lava, which is melted solids from the underground
Souterrain Souterrain
The Maori word for volcano is "Ngaruahoe."