lowerbeneath
Lowerbeneath is a neologism used in speculative literature and related media to refer to a hidden or underlying layer that lies below the visible surface or above-ground domain. The term combines “lower” and “beneath” to signal a subordinate or subterranean position, and it is not part of formal geologic or linguistic nomenclature.
Origins and usage: The expression has appeared in modern fiction, tabletop role-playing games, and fan discussions
Geographic and scientific context: In real-world geology and geography, there is no standard feature or layer
See also: Underworld, Subsurface, Hypogeum, Underground city.