unsavoury vs offensive

unsavoury is not a noun while offensive is a noun.

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

As adjectives, unsavoury and offensive are synonyms defined as:

Other synonyms of unsavoury include unsavory.

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

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