Which term describes a vertical line in geometry?

The term that correctly describes a vertical line in geometry is "Axis." In geometry and graphing, an axis refers to a reference line against which measurements are made and is typically used in the context of coordinate systems. In a Cartesian plane, the vertical axis is often referred to as the y-axis, while the horizontal line is the x-axis. This terminology is crucial because it helps define the position of points in a two-dimensional space, allowing for a clear understanding of geometric relationships and functions.

The other terms refer to different concepts. "Line" describes a straight one-dimensional figure extending infinitely in both directions, but it does not specify orientation. "Column" generally relates to a vertical arrangement of data, often seen in tables or databases, while "Row" pertains to a horizontal arrangement. Thus, the correct term that specifically designates a vertical line is axis.