Adjective subterranean has 2 senses
- subterranean, subterraneous - being or operating under the surface of the earth; "subterranean passages"; "a subsurface flow of water"
Antonym: overhead (indirect, via surface, subsurface)
Antonym: surface (indirect, via subsurface, overhead)
- subterranean, subterraneous, ulterior - 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
Antonyms: overt, open (indirect, via covert)
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