Definitions

1. noun

a deep, hidden, and often underground chamber or passage, especially in a mine or a cave

“The explorers stumbled upon an ancient barathron deep within the cave system.”

2. noun

a deep, underground chamber of a volcano, especially one containing lava

“The barathron of the volcano was filled with bubbling lava, emitting a loud roar.”

3. noun

a deep, underground room or compartment, especially one used as a hiding place or secret chamber

“The secret barathron beneath the castle was a place of refuge for the royal family.”