from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Geology The mass of rock underlying a mineral deposit in a mine.
- n. Geology The underlying block of a fault having an inclined fault plane.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The section of rock that extends below a diagonal fault line (the corresponding upper section being the hanging wall).
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the lower wall of an inclined fault
foot + wall (Wiktionary)