refuse vs repudiate

refuse is a noun but repudiate is not a noun.

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

As verbs, repudiate is a hyponym of refuse; that is, repudiate 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, regret, disobey.

refuse (noun)	repudiate (noun)
food that is discarded (as from a kitchen)

refuse (verb)	repudiate (verb)
show unwillingness towards	refuse to acknowledge, ratify, or recognize as valid
not accept as true	cast off
refuse to let have	reject as untrue, unfounded, or unjust
refuse entrance or membership	refuse to recognize or pay
elude, especially in a baffling way
resist immunologically the introduction of some foreign tissue or organ