Source : WordNet®

gold rush
     n 1: 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 lik an assembly
          line" [syn: {boom}, {bonanza}, {gravy}, {godsend}, {manna
          from heaven}, {windfall}, {bunce}]
     2: a large migration of people to a newly discovered gold field