Ostiarium
Ostiarium one form of Tributum, Capitis [see VECTIGALIA]. A tax imposed in Cilicia, Syria, and perhaps some other provinces, upon doorways, whose number was probably regarded as a sign of the value of the property. (Compare the English window-tax.) Nothing is known of the amount. The word ostiarium is found in Caesar, B.C. 3, 32. Cic. Fam. 3.8, 5, speaks of exactio ostiorum.
From William Smith (ed.), Dictionary of Greek and Roman Antiquities. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.