refuse vs disobey

refuse is a noun but disobey is not a noun.

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

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

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

refuse (verb)	disobey (verb)
show unwillingness towards	refuse to go along with; refuse to follow; be disobedient
not accept as true
refuse to let have
refuse entrance or membership
elude, especially in a baffling way
resist immunologically the introduction of some foreign tissue or organ