misfortune vs mishap

misfortune and mishap both are nouns.

Word	Noun	Adjective	Verb	Adverb
misfortune	Yes	No	No	No
mishap	Yes	No	No	No

As nouns, mishap is a hyponym of misfortune; that is, mishap is a word with a more specific, narrower meaning than misfortune:

misfortune: unnecessary and unforeseen trouble resulting from an unfortunate event
mishap: an instance of misfortune

misfortune (noun)	mishap (noun)
unnecessary and unforeseen trouble resulting from an unfortunate event	an instance of misfortune
an unfortunate state resulting from unfavorable outcomes	an unpredictable outcome that is unfortunate