agonic line
/əˈgɒnɪk/noun
- an imaginary line round the earth passing through both the north pole and the north magnetic pole, at any point on which a compass needle points to true north无偏线, 零磁偏线。
词源
mid 19th cent.: from Greek agōnios, agōnos (from a- 'without'+gonia 'angle')+-IC.