1.A line on a map or drawing indicating a horizontal plane of constant elevation. All points on a contour line are at the same elevation.
2.A line on a map or drawing indicating a horizontal plane of constant elevation. All points on a contour line are at the same elevation. In the drawing below the bottom drawing is a map of contour lines. The top drawing (the side view) is a section. Also see SECTION and ELEVATION (1)
EXAMPLE:
In the illustration below the bottom drawing is a map of contour lines.
