"outer fortification of a city or castle," mid-13c., from Old French barbacane (12c.), a general Romanic word, perhaps ultimately from Arabic or Persian (compare bab-khanah "gate-house"). Watkins identifies it as from Old Iranian *pari-varaka "protective," from *wor-o-, suffixed variant form of PIE root *wer- (5) "to cover" (see wier).[barbican etymology, barbican origin, 英语词源]