Portus

From the Latin Portus, presumably from portus (“harbour, port”).

• (Received Pronunciation, UK) IPA^(key): /ˈpɔːtəs/

Portus

1. (historical) A large artificial harbour of Ancient Rome, situated on the north bank of the mouth of the River Tiber, established and enlarged (respectively) by the Emperors Claudius (10 BC–AD 54) and Trajan (AD 53–117), and connected to the Pons Aemilius of Rome by the Via Portuensis.

• Ostia

• Portus on Wikipedia.Wikipedia

• Troups, Proust, Stroup, sprout, Sprout, stupor, surtop

Presumably a use as a proper noun of the common noun portus (“harbour”, “port”).

• (Classical Latin) IPA^(key): [ˈpɔr.tʊs]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈpɔr.t̪us]
• Homophone: portus

Portus m sg (genitive Portūs); fourth declension

1. (more fully “Portus Ostiēnsis Augustī” or, later, “Portus Rōmae”) Portus (large artificial harbour of Ancient Rome)

Fourth-declension noun, with locative, singular only.

• English: Portus
• Italian: Porto

• Ostia