offensive vs unsavory

offensive is a noun but unsavory is not a noun.

Word	Noun	Adjective	Verb	Adverb
offensive	Yes	Yes	No	No
unsavory	No	Yes	No	No

As adjectives, offensive and unsavory are synonyms defined as:

Other synonyms of offensive include unsavoury.

offensive (noun)	unsavory (noun)
the action of attacking an enemy

offensive (adjective)	unsavory (adjective)
unpleasant or disgusting especially to the senses	morally offensive
causing anger or annoyance	not pleasing in odor or taste
for the purpose of attack rather than defense
morally offensive
violating or tending to violate or offend against
causing or able to cause nausea