subterrain

Noun

 * 1)  The bedrock or rock layer that lies beneath the soil and superficial features of an area.
 * 2) A cave or underground room.
 * 3) An underground region.
 * 4) An underlying basis or undercurrent.
 * 1) A cave or underground room.
 * 2) An underground region.
 * 3) An underlying basis or undercurrent.
 * 1) An underground region.
 * 2) An underlying basis or undercurrent.
 * 1) An underground region.
 * 2) An underlying basis or undercurrent.
 * 1) An underlying basis or undercurrent.
 * 1) An underlying basis or undercurrent.
 * 1) An underlying basis or undercurrent.
 * 1) An underlying basis or undercurrent.