Is immune a verb noun or adverb or adjective?

The Word immune is an adjective, a Word that describes a noun as protected against a specific disease by inoculation or as the result of innate or acquired resistance; not subject to an obligation imposed on others; exempt. The adjective immune is most often used as a predicate adjective, following a linking verb. Examples:

If you have had this disease, you are now immune.

Don't wast your time, he is immune to sweet talk.