sincerity vs singleness

sincerity and singleness both are nouns.

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

As nouns, singleness is a hyponym of sincerity; that is, singleness is a word with a more specific, narrower meaning than sincerity:

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

Other hyponyms of sincerity include heartiness, wholeheartedness, straightforwardness.

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