from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Situated or operating beneath the earth's surface; underground.
- adj. Hidden; secret: subterranean motives for murder.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. below ground, under the earth, underground
from the GNU version of the Collaborative International Dictionary of English
- adj. Being or lying under the surface of the earth; situated within the earth, or under ground
from The Century Dictionary and Cyclopedia
- Situated or occurring below the surface of the earth or under ground.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. being or operating under the surface of the earth
- adj. lying beyond what is openly revealed or avowed (especially being kept in the background or deliberately concealed)
Latin subterrāneus : sub-, sub- + terra, earth; see ters- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)