sincere vs sincerity

sincere is not a noun while sincerity is a noun.

Word	Noun	Adjective	Verb	Adverb
sincere	No	Yes	No	No
sincerity	Yes	No	No	No

sincere (noun)	sincerity (noun)
	the quality of being open and truthful; not deceitful or hypocritical
	the trait of being serious
	a quality of naturalness and simplicity
	an earnest and sincere feeling

sincere (adjective)	sincerity (adjective)
open and genuine; not deceitful
characterized by a firm and humorless belief in the validity of your opinions