fortune vs mishap

fortune and mishap both are nouns.

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

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

fortune: an unknown and unpredictable phenomenon that causes an event to result one way rather than another
mishap: an unpredictable outcome that is unfortunate

Other hyponyms of fortune include bad luck, mischance, even chance, toss-up, tossup.

fortune (noun)	mishap (noun)
an unknown and unpredictable phenomenon that causes an event to result one way rather than another	an instance of misfortune
an unknown and unpredictable phenomenon that leads to a favorable outcome	an unpredictable outcome that is unfortunate
a large amount of wealth or prosperity
your overall circumstances or condition in life (including everything that happens to you)