refuse vs regret

refuse and regret both are nouns.

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

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

Other hyponyms of refuse include disdain, freeze off, pooh-pooh, reject, scorn, spurn, turn down, contract out, repudiate, disobey.

refuse (noun)	regret (noun)
food that is discarded (as from a kitchen)	sadness associated with some wrong done or some disappointment

refuse (verb)	regret (verb)
show unwillingness towards	decline formally or politely
not accept as true	express with regret
refuse to let have	feel remorse for; feel sorry for; be contrite about
refuse entrance or membership	feel sad about the loss or absence of
elude, especially in a baffling way
resist immunologically the introduction of some foreign tissue or organ