hades; realm of the dead; underworld
Refers to the mythological world where spirits of the dead reside, often used in religious, literary, or fantasy contexts.
In Greek mythology, Hades rules the underworld.
He said he saw the realm of the dead during his near-death experience.
katabasis; descent to the underworld
Sino-Japanese compound of 冥 (dark, underworld) and 界 (world, realm). The exact historical derivation is uncertain, but the word is conventionally associated with the concept of a dark afterlife realm.