American Dictionary of the English Language

CORDON, noun [See Cord.]

1. In fortification, a row of stones jutting before the rampart, and the basis of the parapet; or a row of stones between the wall of a fortress which lies aslope, and the parapet which is perpendicular; serving as an ornament, and used only in fortifications of stone-work.

2. In military language, a line or series of military posts; as a cordon of troops.