sincerity vs commitment

sincerity and commitment both are nouns.

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

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

sincerity (noun)	commitment (noun)
the quality of being open and truthful; not deceitful or hypocritical	the act of binding yourself (intellectually or emotionally) to a course of action
the trait of being serious	the official act of consigning a person to confinement (as in a prison or mental hospital)
a quality of naturalness and simplicity	an engagement by contract involving financial obligation
an earnest and sincere feeling	the trait of sincere and steadfast fixity of purpose
	a message that makes a pledge