What does the term "meridian" refer to in land surveying?

In land surveying, the term "meridian" specifically refers to a vertical line that is used as a reference point for land division. It is an essential component of the rectangular survey system, which is used to divide land into townships and sections. The principal meridians in the United States serve as the starting reference lines for this system, allowing surveyors to establish boundaries and describe the location of properties accurately.

In this context, the vertical nature of meridians helps create a grid system when combined with horizontal baselines, producing a structured method to navigate and subdivide land throughout various territories. This precise delineation is crucial for property descriptions in legal documents, ensuring accurate communication about land parcels. Other options, such as horizontal lines or methods of measuring land area, do not accurately describe the role of a meridian in the context of surveying. Therefore, the definition of a meridian as a vertical line used for land division is the correct understanding of the term.