protective vs defensive

protective is not a noun while defensive is a noun.

Word	Noun	Adjective	Verb	Adverb
protective	No	Yes	No	No
defensive	Yes	Yes	No	No

protective (noun)	defensive (noun)
	an attitude of defensiveness

protective (adjective)	defensive (adjective)
intended or adapted to afford protection of some kind	intended or appropriate for defending against or deterring aggression or attack
showing care	attempting to justify or defend in speech or writing
(usually followed by `of') solicitously caring or mindful