What is "coupure"

Coupure \Cou*pure"\ (k??-p?r"), n. [F., fr. couper to cut.] (Fort.) A passage cut through the glacis to facilitate sallies by the besieged.
--Wilhelm.

n. (context fortification English) A passage cut through the glacis to facilitate sally by the besieged.

A coupure is a means of closing an opening in a wall, floodwall or levee (dike). The word comes from the french verb couper which means to cut. In historic times a coupure was a location where a breach in the city walls or the walls of a fortress was closed. In more modern times a coupure is a way of allowing traffic to pass a flood protection structure.