Either, but if you need to pick one it would be noun.
Explanation:
The predicate nominative (or predicate noun) is the noun or pronoun that comes after a linking verb. It renames the subject of the sentence. The sentence should still make sense if you switch the predicate nominative and the subject.
1 I will Approve when I take my Math test. 2 You must have self approval before you can go on an airplane. (to approve, aprroved) Happy to help you! :)
