noun.
In mining, a rich mine or vein of silver or gold.
noun.
The point at which two mother lodes intersect
noun.
By extension, anything which is a mine of wealth or yields a large income or return.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
a sudden happening that brings good fortune (as a sudden opportunity to make money)
noun.
an especially rich vein of precious ore
Word Usage
"But investment banks may not land a profit bonanza from the wave of deals; so many banks are sharing top billing, big profits for bookrunners remain to be seen."