counterscarp

Outer slope of a defensive ditch.

...she had disappeared amid the scaffolding--the scaffold--as if it might once have been the glacis of the fort itself, down from the forgotten counterscarp of a dream.

- Malcolm Lowry, October Ferry to Gabriola

Why, the old peer, pox of his tough constitution! (for that would have helped him on,) has made shift by fire and brimstone, and the devil knows what, to force the gout to quit the counterscarp of his stomach, just as it had collected all its strength in order to storm the citadel of his heart.

Lovelace to Belford, Clarissa by Samuel Richardson