refuse vs hold on

refuse is a noun but hold on is not a noun.

Word	Noun	Adjective	Verb	Adverb
refuse	Yes	No	Yes	No
hold on	No	No	Yes	No

As verbs, hold on is a hypernym of refuse; that is, hold on is a word with a broader meaning than refuse:

Other hypernyms of refuse include keep.

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

refuse (verb)	hold on (verb)
show unwillingness towards	be persistent, refuse to stop
not accept as true	stop and wait, as if awaiting further instructions or developments
refuse to let have	hold the phone line open
refuse entrance or membership	hold firmly
elude, especially in a baffling way	retain possession of
resist immunologically the introduction of some foreign tissue or organ