refuse vs withhold

refuse is a noun but withhold is not a noun.

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

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

Other hyponyms of refuse include keep back.

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

refuse (verb)	withhold (verb)
show unwillingness towards	hold back; refuse to hand over or share
not accept as true	retain and refrain from disbursing; of payments
refuse to let have
refuse entrance or membership
elude, especially in a baffling way
resist immunologically the introduction of some foreign tissue or organ