Scrabble?! ISOHYETAL

Definitions of ISOHYETAL in various dictionaries:

A contour line (also isocline, isopleth, isarithm, or equipotential curve) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional graph of the function f(x, y) parallel to the x, y plane. In cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. A contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes. The contour interval of a contour map is the difference in elevation between successive contour lines.More generally, a contour line for a function of two variables is a curve connecting points where the function has the same particular value.The gradient of the function is always perpendicular to the contour lines. When the lines are close together the magnitude of