The phrase "double closet" refers to a type of storage space that has two sections or compartments for storing things, usually clothes. Full definition
Huge master bedroom with double closet, ensuite bathroom, and extra vanity space. (phoenixrealestateguy.com)
I've got double closet doors in the new entry waiting to be painted. (theinspiredroom.net)
Dress pants complement shirts and blouses, and can even double your closet's outfit combinations with a flair of sophistication. (thechicfashionista.com)