declination

Short definition from Wiktionary

Noun

1. 1
   At a given point, the angle between magnetic north and true north.
2. 2
   At a given point, the angle between the line connecting this point with the geographical center of the earth and the equatorial plane.
3. 3
   A refusal.
4. 4
   Declension.
5. 5
   The act or state of bending downward; inclination.
6. 6
   The act or state of falling off or declining from excellence or perfection; deterioration; decay; decline.
7. 7
   Deviation.