Definitions
1.nounAt a given point, the angle between magnetic north and true north.
2.nounAt a given point, the angle between the line connecting this point with the geographical center of the earth and the equatorial plane.
3.nounA refusal.
4.noun(grammar) Declension.
5.nounThe act or state of bending downward; inclination."declination of the head"
6.nounThe act or state of falling off or declining from excellence or perfection; deterioration; decay; decline.
7.nounDeviation.