1.a small room (or recess) or cabinet used for storage space
2.a toilet in England
3.a tall piece of furniture that provides storage space for clothes; has a door and rails or hooks for hanging clothes
4.a small private room for study or prayer
5.(of information) given in confidence or in secret;
closet information
6.indulging only covertly;
a closet alcoholic
1.confine to a small space, as for intensive work