mother lode definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
the main lode, or vein of ore, in a particular region or district
mother lode definition by American Heritage Dictionary
- The main vein of ore in a region.
- An abundant or rich source: “the kind . . . who makes Boston the mother lode of advance men” (David Nyhan).