serendipity vs fluke

serendipity and fluke both are nouns.

Word	Noun	Adjective	Verb	Adverb
serendipity	Yes	No	No	No
fluke	Yes	No	No	No

As nouns, fluke is a hypernym of serendipity; that is, fluke is a word with a broader meaning than serendipity:

Other hypernyms of serendipity include good fortune, good luck.

serendipity (noun)	fluke (noun)
good luck in making unexpected and fortunate discoveries	parasitic flatworms having external suckers for attaching to a host
	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