late Old English castel "village" (this sense from a biblical usage in Vulgar Latin); later "large building or series of connected buildings fortified for defense, fortress, stronghold" (late Old English), in this sense from Old North French castel (Old French chastel, 12c.; Modern French château), from Latin castellum "a castle, fort, citadel, stronghold; fortified village," diminutive of castrum "fort," from Proto-Italic kastro- "part, share;" cognate with Old Irish cather, Welsh caer "town" (probably related to castrare via notion of "cut off," from PIE root kes- "to cut"). In early bibles, castle was used to translate Greek kome "village."