noun.
A slope extending down from a fortification.
noun.
A neutral area separating conflicting forces.
The Century Dictionary and Cyclopedia
noun.
A gentle slope or sloping bank.
noun.
An easy slope, like that of the shingle piled on the shore by the action of the tides and waves, less steep than a talus.
the GNU version of the Collaborative International Dictionary of English
noun.
A gentle slope, or a smooth, gently sloping bank; especially (Fort.), that slope of earth which inclines from the covered way toward the exterior ground or country (see Illust. of ravelin).