bonanza vs gold rush

bonanza and gold rush both are nouns.

Word	Noun	Adjective	Verb	Adverb
bonanza	Yes	No	No	No
gold rush	Yes	No	No	No

As nouns, bonanza and gold rush are synonyms defined as:

bonanza and gold rush: a sudden happening that brings good fortune (as a sudden opportunity to make money)

Other synonyms of bonanza include boom, bunce, godsend, gravy, manna from heaven, windfall.

bonanza (noun)	gold rush (noun)
a sudden happening that brings good fortune (as a sudden opportunity to make money)	a large migration of people to a newly discovered gold field
an especially rich vein of precious ore	a sudden happening that brings good fortune (as a sudden opportunity to make money)