| 1 | Middle English | Portesmuða | — |
| 2 | Old English | Portesmuða | — |
| 3 | Old English | port | a port, a haven; a town, particularly one with... |
| 4 | Latin | porta | gate, especially of a city; entrance, passage,... |
| 5 | Proto-Indo-European | per- | before, in front; first; to go through |
| 6 | Proto-Indo-European | pr̥tós | passed , crossed |