1. (

• bonanza

) an especially rich vein of precious ore ;

2. (

• boom ,
• bonanza ,
• gold_rush ,
• gravy ,
• godsend ,
• manna_from_heaven ,
• windfall ,
• bunce

) 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" ;