porthmos, i, m.,= πορθμός,
a strait (pure Lat. fretum), Plin. 3, 5, 10, § 74.
Porthmos, i, f., a town of Euboea , Plin. 4, 12, 21, § 64. ...
A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.