lode

1. (obsolete) A way or path; a road.

2. (dialectal) A watercourse.

3. (mining) A vein of metallic ore that lies within definite boundaries, or within a fissure.Examples: "The metals traditionally sought in the Bristol Bay region have been gold and copper, mostly in deposits near Lake Iliamna. An exception is a gold lode discovered about 1930 near Sleitat Mountain (4), where about $200 in gold was recovered from small quartz veins near the periphery of a small granitic intrusive body."

4. (by extension) A rich source of supply.Examples: "In recent years, Jack Grieve of the department of English and linguistics at the University of Birmingham in England has embraced Twitter as a bountiful lode for looking at language-use patterns."