agonic line
- noun
- /ˈæɡənɪk laɪn/
- Specialized
- The location of the agonic line shifts over time due to changes in the Earth's magnetic field.
Examples
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Navigators use charts that mark the agonic line to correct their compass readings.
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On this map, the agonic line is shown passing through parts of South America and the Atlantic Ocean.
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The agonic line runs through several countries.
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Many navigators study the agonic line for accurate mapping.
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Navigators use charts that mark the agonic line to correct their compass readings.
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On this map, the agonic line is shown passing through parts of South America and the Atlantic Ocean.
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The location of the agonic line shifts over time due to changes in the Earth's magnetic field.
Synonyms
A line on a map showing places where compasses point the same amount away from north
A line on the Earth's surface joining places where compasses point the same amount from true north
A line on a map connecting places with the same difference between magnetic north and true north
Surface Forms
Morphology
agonic + line
This is a specialized technical term: 'agonic' is a rare, domain-specific adjective (here meaning points of zero magnetic declination) and its meaning is not transparently derived from everyday morphology. Knowing the general word 'line' does not allow a B1 learner to infer the precise geophysical sense, so the overall expression is unpredictable without prior exposure or specialist knowledge.
Etymology
Agonic line names a line on the Earth where a compass points exactly to true north. The word agonic suggests 'no angle' and the line marks those places, so sailors and navigators use it to know when their compass needs no correction.