πορθμός

A. ferry or place crossed by a ferry, strait, narrow sea, π. Ἰθάκης τε Σάμοιό τε Od. 4.671; of the straits of Salamis, Hdt. 8.76,91; πορθμὸν ἀμείφας Ἕλλας, i.e. the Hellespont, A. Pers. 68(lyr.), cf.722,799; π. Σαρωνικός Id. Ag. 307; ὁ ἐς Ἀΐδα πορθμός the Styx, E. Hec. 1106(lyr.); ὁ π. ὁ περὶ τὴν Σκύλλαν, i.e. the straits of Messina, Pl. Ep. 345e, cf. Arist. Mir. 834b3, Vent. 973b1: hence prov., π. Σικελίας a 'slough of despond', Lib. Ep. 221.1.

b. generally, the sea, Pi. I. 4(3).57.

2. any narrow passage, tube, as of the κλεφύδρα 1, Emp. 100.10, 17.

II. crossing by a ferry, passage, S. Tr. 571, E. Hel. 532(both pl.); χωρεῖ ὁ π. Macho ap.Ath. 8.341c; π. χθονός a passage to it, E. Cyc. 108; οὐ πᾶσι π. αὑτὸς Ἀργείοισιν ἦν; Id. Hel. 127; τηρήσαντες τὸν π. watching for the opportunity to cross, Th. 6.2.