insincere vs buttery

insincere is not a noun while buttery is a noun.

Word	Noun	Adjective	Verb	Adverb
insincere	No	Yes	No	No
buttery	Yes	Yes	No	No

insincere (noun)	buttery (noun)
	a teashop where students in British universities can purchase light meals
	a small storeroom for storing foods or wines

insincere (adjective)	buttery (adjective)
lacking sincerity	resembling or containing or spread with butter
	unpleasantly and excessively suave or ingratiating in manner or speech