A wall.
A pattern-forming ridge on the surface of a pollen grain.
A defensive structure; a protective barrier; a bulwark.
A defensive mound of earth or a wall with a broad top and usually a stone parapet; a wall-like ridge of earth, stones or debris; an embankment for defensive purpose.
That which defends against intrusion from outside; a protection.
A steep bank of a river or gorge.
To defend with a rampart; fortify or surround with a rampart.