The Collaborative International Dictionary
Subterrestrial
Subterrestrial \Sub`ter*res"tri*al\, a. Subterranean.
Wiktionary
subterrestrial
a. Under the earth; subterranean.
Usage examples of "subterrestrial".
Some came from Oort-cloud nomads, but most were from the inner-system colonists who inhabited the asteroidal belts their ancestors had made by pulverizing the subterrestrial planets.