Nar"thex (?), n. [L., giant fennel, Gr. .]
1. Bot.
A tall umbelliferous plant (Ferula communis). See Giant fennel, under Fennel.
2. Arch.
The portico in front of ancient churches; sometimes, the atrium or outer court surrounded by ambulatories; -- used, generally, for any vestibule, lobby, or outer porch, leading to the nave of a church.
© Webster 1913.