1. Plural of isogon; lines on a map connecting points of equal magnetic declination.
Usage: technical; geography/cartography
2. In geometry, polygons having all angles equal.
Usage: mathematics; rare

Examples

• Navigators use isogons on nautical charts to account for magnetic variation.
• The isogons on this map show how magnetic declination changes across the region.
• In geometry, regular polygons are special cases of isogons where all sides are also equal.
• Cartographers draw isogons to help sailors adjust their compass readings.
• The spacing between isogons indicates the rate of change in magnetic declination.