Subterranean (Adjective)
Meaning 1
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.
Classification
All adjective clusters.
Synonyms
Meaning 2
Being or operating under the surface of the earth; "subterranean passages"; "a subsurface flow of water".
Classification
All adjective clusters.