Rampart, n.
Etymology: [F. rempart, OF. rempar, fr. remparer to fortify, se remparer to fence or intrench one's self; re- re- pref. + pref. en- (L. in) + parer to defend, parry, prepare, L. parare to prepape. See Pare.]
1. That which fortifies and defends from assault; that which secures safety; a defense or bulwark.
2. (Fort.)
A broad embankment of earth round a place, upon which the parapet is raised. It forms the substratum of every permanent fortification. Mahan.
Syn. -- Bulwark; fence; security; guard. -- Rampart, Bulwark. These words were formerly interchanged; but in modern usage a distinction has sprung up between them. The rampart of a fortified place is the enceinte or main embankment or wall which surrounds it. The term bulwark is now applied to peculiarly strong outworks which project for the defense of the rampart, or main work. A single bastion is a bulwark. In using these words figuratively, rampart is properly applied to that which protects by walling out; bulwark to that which stands in the forefront of danger, to meet and repel it. Hence, we speak of a distinguished individual as the bulwark, not the rampart, of the state. This distinction, however, is often disregarded.
1 other Webster entry under this spelling
Rampart, v. t. [imp. & p. p. Ramparted; p. pr. & vb. n. Ramparting.]
To surround or protect with, or as with, a rampart or ramparts. Those grassy hills, those glittering dells, Proudly ramparted with rocks. Coleridge. Rampart gun (Fort.), a cannon or large gun for use on a rampart and not as a fieldpiece.
Shades of meaning
Fernald has no entry of its own for rampart; he lists it under barrier, defense.
Where he writes about it:
A parapet is a low or breast-high wall, as about the edge of a roof, terrace, etc., especially, in military use, such a wall for the protection of troops; a rampart is the embankment surrounding a fort, on which the parapet is raised; the word rampart is often used as including the parapet. — from barrier
Bulwark is a general word for any defensive wall or rampart; its only technical use at present is in nautical language, where it signifies the raised side of a ship above the upper deck, topped by the rail. — from barrier