banlieuen.

banlieue (n.)French, "suburbs, precincts," from Vulgar Latin *banleuca, from ban (see ban (n.1)) + leuca "a league (of distance)," in Medieval Latin, "indefinite extent of territory" (see league (n.2)). So, "the extent of a ban; the territory within which a ban is of force," hence, "territory subject to one jurisdiction."