rebuff vs disdain

rebuff and disdain both are nouns.

Word	Noun	Adjective	Verb	Adverb
rebuff	Yes	No	Yes	No
disdain	Yes	No	Yes	No

As verbs, disdain is a hypernym of rebuff; that is, disdain is a word with a broader meaning than rebuff:

Other hypernyms of rebuff include freeze off, pooh-pooh, reject, scorn, spurn, turn down.

rebuff (noun)	disdain (noun)
a deliberate discourteous act (usually as an expression of anger or disapproval)	a communication that indicates lack of respect by patronizing the recipient
an instance of driving away or warding off	lack of respect accompanied by a feeling of intense dislike

rebuff (verb)	disdain (verb)
reject outright and bluntly	reject with contempt
force or drive back	look down on with disdain