self-abasement vs penance

self-abasement and penance both are nouns.

Word	Noun	Adjective	Verb	Adverb
self-abasement	Yes	No	No	No
penance	Yes	No	No	No

As nouns, self-abasement and penance are synonyms defined as:

self-abasement and penance: voluntary self-punishment in order to atone for some wrongdoing

Other synonyms of self-abasement include self-mortification.

self-abasement (noun)	penance (noun)
voluntary self-punishment in order to atone for some wrongdoing	voluntary self-punishment in order to atone for some wrongdoing
	a Catholic sacrament; repentance and confession and atonement and absolution
	remorse for your past conduct