Castrum

Etymology

Castrum appears in Oscan and Umbrian, two other Italic languages, suggesting an origin at least as old as Proto-Italic. Julius Pokorny traces a probable derivation from *k̂es-, 'cut', in *k̂es-tro-m, 'cutting tool'. These Italic reflexes based on *kastrom include Oscan castrous (genitive case) and Umbrian castruo, kastruvuf (accusative case). They have the same meaning, says Pokorny, as Latin fundus, 'estate', 'tract of land', referring to a prepared or cultivated tract, such as a farm enclosed by a fence or wall. Cornelius Nepos uses Latin castrum in that sense: when Alcibiades deserts to the Persians, Pharnabazus gives him an estate (castrum) worth 500 talents in tax revenues. This is a change of meaning from the reflexes in other languages, which still mean some sort of knife, axe, or spear. Pokorny explains it as "a camp, as a cut-off piece of land".