narthex (n.)

"porch at the west end of early churches," the end furthest from the sanctuary (used by penitents not admitted to the body of the church), 1670s, from Late Greek narthex, in classical Greek "giant fennel," a word of unknown origin, perhaps Pre-Greek. The architectural feature allegedly was so called from the fancied resemblance of the porch to a hollow stem. The word also was used in Greek to mean "a small case for unguents, etc." According to Hesiod ("Theogeny"), Prometheus conveyed fire from Heaven to Earth in hollow fennel stalks. Related: Narthecal.