epistolary vs informal

epistolary and informal both are adjectives.

Word	Noun	Adjective	Verb	Adverb
epistolary	No	Yes	No	No
informal	No	Yes	No	No

epistolary (adjective)	informal (adjective)
written in the form of or carried on by letters or correspondence	not formal
	used of spoken and written language
	having or fostering a warm or friendly and informal atmosphere
	not officially recognized or controlled