Definition
The direction toward the Earth's north magnetic pole, which is the point a magnetic compass needle aligns with. Magnetic north is not at the same location as true north (the geographic North Pole), and its position shifts slowly over time. The angular difference between magnetic north and true north at any given location is called variation.
Plain English
The direction your compass points to. It's close to the geographic North Pole but not exactly the same place, and the difference between the two is what causes variation on a chart.
Context Anchor
Seen in navigation, chart reading, compass use, and discussions of variation, which is the angle between true north and magnetic north.
Derivation
From the Latin magneticus, relating to the lodestone — a naturally magnetised rock that aligns itself north–south when free to rotate. Early sailors noticed this alignment, and the direction the stone pointed became known as magnetic north. The term reminds us that this is a magnetism-based reference, not a geographic one.
Why Pilots Care
Headings and courses are flown magnetically, so failing to distinguish MN from true north leads to navigation errors.
Intuition Check
Do not assume “north” always means the top of the map or the geographic North Pole. Magnetic north means the compass-based north direction at your location.
Example Sentence 1
After plotting the course in true degrees, the pilot applied variation to convert it to a magnetic heading referenced to MN.
Example Sentence 2
Before takeoff the student pilot confirmed the runway heading matched the MN reference on the chart.