Bulwark
BUL'WARK, noun
1. In fortification, a bastion, or a rampart; a mound of earth round a place, capable of resisting cannon shot, and formed with bastions, curtains, etc.
2. A fortification; also, any means of defense; as, a navy is the bulwark of a nation.
3. That which secures against an enemy or external annoyance; a screen or shelter; means of protection and safety.
Salvation will God appoint for walls and bulwarks. Isaiah 26:1.
BUL'WARK, verb transitive To fortify with a rampart; to secure by a fortification; to protect.