An enclosed passageway can be referred to as a narthex (7 letters) or a DUCT (4 letters). A narthex is an area at the entrance of a church, typically located between the outer door and the inner door of the main building. It is often used as a gathering place for worshipers before and after services. A DUCT is a tube or conduit that is used to transport air, liquids, or other materials from one place to another. Ducts are commonly found in heating, ventilation, and air conditioning systems.