good fortune vs fluke

good fortune and fluke both are nouns.

Word	Noun	Adjective	Verb	Adverb
good fortune	Yes	No	No	No
fluke	Yes	No	No	No

As nouns, good fortune and fluke are synonyms defined as:

Other synonyms of good fortune include good luck.

good fortune (noun)	fluke (noun)
a stroke of luck	parasitic flatworms having external suckers for attaching to a host
an auspicious state resulting from favorable outcomes	either of the two lobes of the tail of a cetacean
	flat bladelike projection on the arm of an anchor
	a barb on a harpoon or arrow
	a stroke of luck