What is "faussebraye"

n. (context military English) A second rampart, exterior and parallel to the main rampart, and considerably below its level.

A faussebraye is a defensive wall located outside the main walls of a fortification. It is of a lower height than the main walls, and is preceded by a ditch. In Greek and Byzantine fortifications, the faussebraye was known as a proteichisma.