What is the meaning of Bulwark?

A defensive wall or rampart.

A defense or safeguard.

A breakwater.

The planking or plating along the sides of a nautical vessel above her gunwale that reduces the likelihood of seas washing over the gunwales and people being washed overboard.

Any means of defence or security.

To fortify something with a wall or rampart.

To provide protection of defense for something.

Source: wiktionary.org