declination

/ˌdɛklɪˈneɪʃən/

At a given point, the angle between magnetic north and true north.

At a given point, the angle between the line connecting this point with the geographical center of the earth and the equatorial plane.

A refusal.

(grammar) Declension.

The act or state of bending downward; inclination.

declination of the head

The act or state of falling off or declining from excellence or perfection; deterioration; decay; decline.

Deviation.