1. Lines on a map or chart connecting points of equal value for a particular variable, such as temperature, pressure, or elevation.
Usage: Plural form; commonly used in geography, meteorology, and cartography.; Also called contour lines or isograms depending on context.

Examples

• The weather map displayed isolines showing areas of equal atmospheric pressure.
• Isolines on topographic maps help hikers understand the steepness of terrain.
• Temperature isolines on the climate chart revealed a gradual warming trend from north to south.
• Meteorologists use isolines to identify weather patterns and predict storm systems.
• The isolines on the elevation map made it easy to spot mountain ranges and valleys.
• In oceanography, isolines represent depths where water temperature remains constant.