supply closet(n = noun.artifact) - a closet for storing supplies;
is a kind of closet, cupboard

broom closet, building supply house, building supply store, china closet, closet, closet auger, closet drama, closet queen, clothes closet, coat closet, come out of the closet, in short supply, money supply, skeleton in the closet, supply, supply chamber, supply depot, supply line, supply officer, supply route, supply ship, switching power supply, water closet, water supply