Lewis Short
ĕpĭtŏnĭum | ĕpistŏmion (noun N) : ἐπιτόνιον (also written = ἐπιστόμιον)
* A bung, stopple, the cock in a water-pipe, Varr. R. R. 3, 5, 16; Vitr. 9, 8, 11 al.; Sen. Ep. 86, 6; Dig. 19, 1, 17, § 8.
Charlton T. Lewis, Charles Short, A Latin Dictionary