cavern
n. countablen. a very large cave, often found deep underground. It feels much bigger and more impressive than a normal cave.
n. a large cave or a chamber in a cave, typically formed by the underground erosion of rock. Often implies a sense of vastness or depth compared to a standard cave.
The hikers explored the dark cavern with their flashlights.
Water dripping from the ceiling of the cavern has created massive limestone pillars over thousands of years.
As the explorers descended deeper into the limestone system, they emerged into a vast cavern where the echoes of their voices seemed to travel for miles.
From Middle English caverne, borrowing from Old French caverne, from Latin caverna (“hollow, cavity, cave”), from cavus (“hollow, excavated, concave”).
Often used metaphorically to describe any large, dark, or hollow space.