subterraneous

Adj.	1.	subterraneous - being or operating under the surface of the earth; "subterranean passages"; "a subsurface flow of water" Synonyms: subterranean
	2.	subterraneous - lying beyond what is openly revealed or avowed (especially being kept in the background or deliberately concealed); "subterranean motives for murder"; "looked too closely for an ulterior purpose in all knowledge"- Bertrand Russell Synonyms: ulterior, subterranean