What is Closet ?
Closet is (noun) US a cupboard Will you get my coat from the closet, honey? to come out of the closet to say publicly that you are homosexual (informal.)(adj) secret, not revealing something in public He’s a closet racist. Synonym secret(verb) to closet yourself with someone to shut yourself away in a room with someone The directors have been closeted with the VAT inspectors for several hours.
source: Easier English, Student Dictionary Upper Intermediate Level