An entry space, foyer, or anteroom of a church between the door and the nave. The term is from the Greek for a "small case." Historically, the narthex was an enclosed vestibule or porch of a basilica. Catechumens and penitents stood in the narthex during the service. It also may serve as a place for the gathering and formation of processions and a place for people to wait before services begin.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from "An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians," Don S. Armentrout and Robert Boak Slocum, editors.