Predicative noun phrase

Predicative noun phrase is a noun phrase which is used as a predicate, rather than as a referring expression.

Example
in he is the boss, meaning that he is in charge, the noun phrase the boss is used predicatively (it denotes a property). In the sentence the boss will have to deal with that, (meaning that whoever is (going to be) the boss, he will have to deal with that), the boss is also taken as a predicative noun phrase.

Links
Utrecht Lexicon of Linguistics