Definition
to demarcate an area by placing a boundary around it
劃出；隔開
We need to mark off this area for construction.
我們需要把這個區域劃分出來進行施工。
She marked off a section of the garden with a rope.
她用繩子把花園的一部分隔開。
For safety, we marked off a perimeter around the quarantine area.
為了安全起見，我們在隔離區周圍劃定了周界。