mishap vs accident

mishap and accident both are nouns.

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

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

Other hyponyms of mishap include near miss, derailment, ground loop, puncture, slip, trip, crash.

mishap (noun)	accident (noun)
an instance of misfortune	anything that happens suddenly or by chance without an apparent cause
an unpredictable outcome that is unfortunate	an unfortunate mishap; especially one causing damage or injury