subterranean

Từ điển WordNet v3.1 - WordNet Dictionary

adjective

1. being or operating under the surface of the earth
- subterranean passages
- a subsurface flow of water
• Syn:
subterraneous
• Similar to:
subsurface
2. 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
• Syn:
subterraneous, ulterior
• Similar to:
covert

• Từ đồng nghĩa / Synonyms:
  subterraneous, ulterior