Bulwark

1. A rampart; a fortification; a bastion or outwork. (Fort.)
2. That which secures against an enemy, or defends from attack; any means of defense or protection.

   The royal navy of England hath ever been its greatest defense, . . . the floating bulwark of our island.

3. The sides of a ship above the upper deck, usually a fencelike structure around the deck. (Naut.)

imp. & p. p. Bulwarked; p. pr. & vb. n. Bulwarking

1. To fortify with, or as with, a rampart or wall; to secure by fortification; to protect.

   Of some proud city, bulwarked round and armed With rising towers.