barbette

n. [ F. Cf. Barbet. ] (Fort.) A mound of earth or a platform in a fortification, on which guns are mounted to fire over the parapet. [ 1913 Webster ]

En barbette,
In barbette, said of guns when they are elevated so as to fire over the top of a parapet, and not through embrasures. --
Barbette gun, or
Barbette battery, a single gun, or a number of guns, mounted in barbette, or partially protected by a parapet or turret. --
Barbette carriage, a gun carriage which elevates guns sufficiently to be in barbette. [ See Illust. of Casemate. ] [ 1913 Webster ]