Source : Webster's Revised Unabridged Dictionary (1913)

Contour \Con*tour"\, n. [F. contour, fr. contourner to mark the
   outlines; con- + tourner to turn. See {Turn}.]
   1. The outline of a figure or body, or the line or lines
      representing such an outline; the line that bounds;
      periphery.

            Titian's coloring and contours.       --A. Drummond.

   2. (Mil.) The outline of a horizontal section of the ground,
      or of works of fortification.

   {Contour feathers} (Zo["o]l.), those feathers that form the
      general covering of a bird.

   {Contour of ground} (Surv.), the outline of the surface of
      ground with respect to its undulation, etc.

   {Contour line} (Topographical Suv.), the line in which a
      horizontal plane intersects a portion of ground, or the
      corresponding line in a map or chart.

Source : WordNet®

contour line
     n : a line drawn on a map connecting points of equal height
         [syn: {contour}]