A more thorough explanation:

Definition: A merestone, also spelled mearstone, is an archaic term used to describe a stone that is used to mark land boundaries.

• When the farmers divided their land, they placed a merestone at each corner to mark the boundaries.
• The surveyor used a merestone to mark the boundary between the two properties.

These examples illustrate how a merestone is used to mark the boundaries of a piece of land. In the first example, the farmers used merestones to divide their land into separate plots. In the second example, the surveyor used a merestone to mark the boundary between two properties. Merestones were commonly used in the past to establish property lines and are still used today in some areas.