Orificium, orificij, n. g. Macrob.The mouth or brinune of a thing.
Lewis and Short: Latin dictionary
ōrĭfĭcĭum, ii, n. [1. os-facio], an opening, orifice (post-class.): ventris sunt duo orificia, Macr. S. 7, 4: cistulae, App. M. 9, p. 236, 41; 11, p. 262, 27.