What is another word for sub-terrestrial?
Pronunciation: [sˈʌbtəɹˈɛstɹɪəl] (IPA) 
The term "sub-terrestrial" refers to something that is situated beneath the earth's surface. When looking for synonyms to this word, one could use phrases such as "subterranean", "underground", or "earthbound". Other options may include "cavernous", "chthonic", "abyssal", or "subsurface". Referring to creatures or vegetation living or growing beneath the earth's surface, synonyms could include "subterranean fauna/flora", "hypogean", or "subsurface life". In terms of describing a location, one might use phrases such as "cave system", "underground cave", or "subsurface cavern". Regardless of the context, there are a variety of synonyms available to denote a sub-terrestrial presence.
