Counterscarp \Coun"ter*scarp`\ (koun`t[~e]r*sk[aum]rp`) n.
[Counter- + scarp: cf. F. contrescarpe.] (Fort.)
The exterior slope or wall of the ditch; -- sometimes, the
whole covered way, beyond the ditch, with its parapet and
glacis; as, the enemy have lodged themselves on the
counterscarp.
[1913 Webster]