Let's say I have a sentence about a person who works for a company. I might say something along the lines of "Jim is an employee." In this sentence, "Jim" is effectively being assigned the role of "employee." Is there a technical term for what the word "employee" would be in the context of this sentence?
In "Jim is an employee," "employee" is a predicate noun.
A predicate noun is a noun (or noun phrase) that is used to predicate a description or identification of the subject.
English grammar often requires nouns to be accompanied by articles, and usually requires a predicate noun to be accompanied by an inflected form of the copular auxiliary "to be." The predicate noun along with these associated elements consistutes the predicate of the sentence ("is an employee"), which predicates, or says something about, the subject of the sentence ("Jim").