Contour

1. An imaginary line, or a line on a map or chart, that connects points of equal value, e.g., elevation of the land surface above or below some reference value or datum plane, generally sea level. Contours are commonly used to depict topographic or structural surfaces; they can also readily show the laterally variable properties of sediments or any other phenomenon that can be quantified. CF: structure contour Syn: contour line
2. The outline or configuration of a surface feature seen two-dimensionally, e.g., the contour of a mountain pass or a coastline.AGI
3. A line drawn through points of equal elevation on any surface. It is the intersection of a horizontal plane with the surface. Rice, 1
4. A line or a surface at all points of which a certain quantity, otherwise variable, has the same value (as lines of equal elevation on the ground or isothermal surfaces in a heat-conducting solid).Webster 3rd
5. As a verb, to construct (as a road) in conformity to a contour. To provide (as a map) with contours (contour lines). To draw or to plot a contour. Webster 3rd
6. The profile or cross-sectional outline of a bit face. Long

Source: Dictionary of Mining, Mineral, and Related Terms