To provide protection of defense for something.
To fortify something with a wall or rampart.
A defensive wall or rampart.
A defense or safeguard.
A breakwater.
Any means of defence or security.
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.
To occupy with troops.
To convert into a military fort.
To assign troops to a military post.
The troops stationed at such a post.
A permanent military post.
Occupants.
A military unit, nominally headed by a colonel, equivalent to a USAF support wing, or an army regiment.