Geometric terms of location

Geometric terms of location describe directions or positions relative to the shape of a particular object. These terms are used in descriptions of engineering, physics, and other sciences, as well as ordinary day to day discourse.

Though these terms by themselves may be somewhat ambiguous, they are usually used in a context in which their meaning is clear. For example, when referring to a drive shaft it is clear what is meant by axial or radial directions. Or, in a free body diagram, one may similarly infer a sense of orientation by the forces or other vectors represented.

Common geometric terms of location are:

• Axial - along the center of a round body, or the axis of rotation of a body
• Azimuthal or Circumferential - following around a curve or circumference of an object. For instance, the pattern of cells in Taylor–Couette flow varies along the azimuth of the experiment.* Lateral - spanning the width of a body.
• Lineal - following along a given path. The shape of the path is not necessarily straight (compare to linear). For instance, a length of rope might be measured in lineal meters or feet.
• Longitudinal - spanning the length of a body. The distinction between width and length may be unclear out of context.
• Radial - along a direction pointing along a radius from the center of a object.