Isoline

isoline - [cartography] A line connecting points of equal value on a map. Isolines fall into two classes: those in which the values actually exist at points, such as temperature or elevation values, and those in which the values are ratios that exist over areas, such as population per square kilometer or crop yield per acre. The first type of isoline is specifically called an isometric line or isarithm; the second type is called an isopleth.

[Category=Geospatial ]

Source: esri, 22 May 2012 09:45:13, http://support.esri.com/en/knowledgebase/GISDictionary/term/abbreviation