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