Found:
predicative noun phrase
SYNTAX: 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.