Fence off
Definition 1 of 2
Pro Tip 1/3Physical Barrier
Emphasizes creating an actual barrier with a fence to separate areas. 
They fenced off the vegetable patch to keep rabbits out.
Pro Tip 2/3Land Ownership
Used to identify or claim ownership of a piece of land. 
The new landowner fenced off fifty acres for a future orchard.
Pro Tip 3/3Safety Measure
Highlights how fences can protect something from outside threats. 
The chemical plant fenced off its perimeter for safety.