Textual thesaurus for "subterraneous"

(adj) ulterior, subterranean

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

(adj) subterranean

being or operating under the surface of the earth

subterranean passages; a subsurface flow of water