rebuff vs spurn

rebuff is a noun but spurn is not a noun.

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

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

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

rebuff (noun)	spurn (noun)
a deliberate discourteous act (usually as an expression of anger or disapproval)
an instance of driving away or warding off

rebuff (verb)	spurn (verb)
reject outright and bluntly	reject with contempt
force or drive back