offensive vs sickening

offensive is a noun but sickening is not a noun.

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

As adjectives, offensive and sickening are synonyms defined as:

Other synonyms of offensive include loathsome, nauseating, nauseous, noisome, queasy, vile.

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

offensive (adjective)	sickening (adjective)
unpleasant or disgusting especially to the senses	causing or able to cause nausea
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