Where does “Porthmus” come from?

Porthmus (Latin) comes from Ancient Greek Πορθμός, from Ancient Greek περάω, from Ancient Greek πέρα, from Proto-Indo-European per-, from Proto-Indo-European pr̥tós — passed , crossed.

Porthmus (Latin): A harbour of Euboea situated opposite to Rhamnus

Definitions

A harbour of Euboea situated opposite to Rhamnus

Ancestry of “Porthmus”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Πορθμός	Porthmus, Euboea, Greece
2	Ancient Greek	περάω	to go from one side to another; to pass through...
3	Ancient Greek	πέρα	beyond
4	Proto-Indo-European	per-	before, in front; first; to go through
5	Proto-Indo-European	pr̥tós	passed , crossed

Every word from Proto-Indo-European pr̥tós →Every word from Proto-Indo-European per- →Every word from Ancient Greek πέρα →