To enclose means to surround something completely or place it inside something else. When you build a fence around your backyard, you enclose the space to keep your dog from running away. When pioneers enclosed their farmland with wooden rails, they were marking boundaries and keeping livestock contained.

The word also describes putting something inside an envelope or package. If you write a letter to your grandmother and enclose a drawing you made, you're placing the drawing inside the envelope with the letter. A note might say, “Please find the enclosed report,” meaning the report is tucked inside.

In older writing, you'll sometimes see enclosure used to describe a historical process where common lands that everyone could use were fenced off and made private property. This was especially important in English history, where enclosing fields changed how people farmed and lived.

Notice that enclose suggests creating a complete boundary. A half-built fence doesn't truly enclose anything. When something is fully enclosed, it's surrounded on all sides, like a bird in a cage or a letter sealed in an envelope.