portorium

From porta (“gate”), or, as it appears in Plautus, possibly from an earlier stage of the language having an equivalent etymology.

portōrium n (genitive portōriī); second declension

1. (in Roman Republic) port duty, levie paid by ships to finance upkeep of public harbours
2. (in Roman Empire) 1/40 (2.5%) custom-tax on trade between Roman provinces

Second declension.

• portorium in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• portorium in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• portorium in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition, 1883–1887)
• portorium in Gaffiot, Félix (1934) Dictionnaire Illustré Latin-Français, Hachette
• portorium in Harry Thurston Peck, editor (1898) Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
• portorium in William Smith et al., editor (1890) A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin