antemurale

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.

antĕ-mūrāle, is, n.,

a protecting wall , an outwork , breastwork (eccl. Lat.), Hier. Hom. 2: murus et antemurale, Vulg. Isa. 26, 1: luxitque antemurale, ib. Thren. 2, 8.