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

• bittercress
• bitterish
• bitterly
• bittern
• bitterness
• bitternut
• bitternut hickory
• bitterroot
• bitters
• bittersweet
• bittersweet chocolate
• bittersweet nightshade
• bitterweed
• bitterwood
• bitterwood tree
• bitthead
• bittie
• bitty
• bitumastic
• bitumen
• bitumenoid
• bituminise
• bituminize
• bituminoid
• bituminous