/ bəˈnænzə; NAmE / noun [ sing. ]
1.
a situation in which people can make a lot of money or be very successful :
a cash bonanza for investors
a bonanza year for the computer industry
2.
a situation where there is a large amount of sth pleasant :
the usual bonanza of sport in the summer
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WORD ORIGIN
early 19th cent. (originally US, especially with reference to success when mining): from Spanish , literally fair weather, prosperity , from Latin bonus good.