1. An imaginary line connecting points on the Earth's surface where the magnetic declination is the same
   - isogonic line, isogonal line

Derived forms: isogones

Type of: line

• Republic of Austria
• Republic of Azerbaijan
• Republic of Belarus
• Republic of Benin
• Republic of Bolivia
• Republic of Bosnia and Herzegovina
• Republic of Botswana
• Republic of Bulgaria
• Republic of Burundi
• Republic of Cameroon
• Republic of Cape Verde
• Republic of Chad
• Republic of Chile
• Republic of China
• Republic of Colombia
• Republic of Costa Rica
• Republic of Cote d'Ivoire
• Republic of Croatia
• Republic of Cuba
• Republic of Cyprus
• Republic of Djibouti
• Republic of Ecuador
• Republic of El Salvador
• Republic of Equatorial Guinea
• Republic of Estonia