offense vs rebuff

offense and rebuff both are nouns.

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

As nouns, rebuff is a hyponym of offense; that is, rebuff is a word with a more specific, narrower meaning than offense:

offense: a lack of politeness; a failure to show regard for others; wounding the feelings of others
rebuff: a deliberate discourteous act (usually as an expression of anger or disapproval)

Other hyponyms of offense include derision, ridicule, indelicacy, insolence, affront, insult, presumption, slight.

offense (noun)	rebuff (noun)
the action of attacking an enemy	a deliberate discourteous act (usually as an expression of anger or disapproval)
a transgression that constitutes a violation of what is judged to be right	an instance of driving away or warding off
a lack of politeness; a failure to show regard for others; wounding the feelings of others
a feeling of anger caused by being offended
the team that has the ball (or puck) and is trying to score

offense (verb)	rebuff (verb)
	reject outright and bluntly
	force or drive back