regret vs contrition

regret and contrition both are nouns.

Word	Noun	Adjective	Verb	Adverb
regret	Yes	No	Yes	No
contrition	Yes	No	No	No

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

Other hyponyms of regret include attrition, contriteness, compunction, remorse, self-reproach.

regret (noun)	contrition (noun)
sadness associated with some wrong done or some disappointment	sorrow for sin arising from fear of damnation

regret (verb)	contrition (verb)
decline formally or politely
express with regret
feel remorse for; feel sorry for; be contrite about
feel sad about the loss or absence of