/beuh nan"zeuh, boh-/ , n.
1. a rich mass of ore, as found in mining.
2. a source of great and sudden wealth or luck; a spectacular windfall: The play proved to be a bonanza for its lucky backers.
[ 1835-45, Amer.; bonacia, equiv. to L bon ( us ) good + ( mal ) acia calm sea malakía softness ( malak ( ós ) soft + -ia -IA) ]