BONANZA
boom, bonanza, gold rush, gravy, godsend, manna from heaven, windfall, bunce
(noun) a sudden happening that brings good fortune (as a sudden opportunity to make money); “the demand for testing has created a boom for those unregulated laboratories where boxes of specimen jars are processed like an assembly line”
bonanza
(noun) an especially rich vein of precious ore
Source: WordNet® 3.1
Etymology
Noun
bonanza (plural bonanzas)
(mining) A rich mine or vein of silver or gold.
Antonym: borrasca
The point at which two mother lodes intersect.
(by extension) Anything which is a mine of wealth or yields a large income or return.
Synonym: mother lode
Source: Wiktionary
Bo*nan"za, n. Etym: [Sp., prop. calm., fair weather, prosperity, fr.
L. bonus good.]
Definition: In mining, a rich mine or vein of silver or gold; hence,
anything which is a mine of wealth or yields a large income. [Colloq.
U. S.]
Source: Webster’s Unabridged Dictionary 1913 Edition