singleness vs sincerity

singleness and sincerity both are nouns.

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

As nouns, sincerity is a hypernym of singleness; that is, sincerity is a word with a broader meaning than singleness:

singleness: without hypocrisy
sincerity: the quality of being open and truthful; not deceitful or hypocritical

singleness (noun)	sincerity (noun)
the quality of concentrating on one central objective	the quality of being open and truthful; not deceitful or hypocritical
without hypocrisy	the trait of being serious
	a quality of naturalness and simplicity
	an earnest and sincere feeling