an especially rich vein of precious ore
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"
- South Africa's gold and mineral bonanza is beginning to tail off .
- Bargain hunters enjoyed a real bonanza today.
- What a bonanza for the winning ticket holders!
- His business was far from being a bonanza!
- It's been a bonanza year for the tourist trade.
- bonanza farming 粗放耕作