accident vs accidental

accident and accidental both are nouns.

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

accident (noun)	accidental (noun)
anything that happens suddenly or by chance without an apparent cause	a musical notation that makes a note sharp or flat or natural although that is not part of the key signature
an unfortunate mishap; especially one causing damage or injury

accident (adjective)	accidental (adjective)
	not of prime or central importance
	happening by chance or unexpectedly or unintentionally