Lewis & Short

con-caedes, ium (sing. abl. concaede, Amm. 16, 12, 15), f., an abattis, barricade of felled trees (post-Aug.), Amm. 16, 12, 15; 17, 10, 6.
Plur., Veg. Mil. 3, 22; Tac. A. 1, 50; Amm. 16, 11, 8.