informality vs informal

informality is a noun but informal is not a noun.

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

informality (noun)	informal (noun)
a manner that does not take forms and ceremonies seriously
freedom from constraint or embarrassment

informality (adjective)	informal (adjective)
	not formal
	used of spoken and written language
	having or fostering a warm or friendly and informal atmosphere
	not officially recognized or controlled