Noun
The act or state of bending downward; inclination; as, declination of the head.
The act or state of falling off or declining from excellence or perfection; deterioration; decay; decline.
The act of deviating or turning aside; oblique motion; obliquity; withdrawal.
The act or state of declining or refusing; withdrawal; refusal; averseness.
The angular distance of any object from the celestial equator, either northward or southward.
The arc of the horizon, contained between the vertical plane and the prime vertical circle, if reckoned from the east or west, or between the meridian and the plane, reckoned from the north or south.
The act of inflecting a word; declension. See Decline, v. t., 4.
Source: Webster's dictionaryA compass is easier to use, though the deviation of the Earth's magnetic field from true north, known as its magnetic declination must be taken into account. Source: Internet
Again, if one is using "true" or map bearings, and the compass does not have preset, pre-adjusted declination, one must additionally add or subtract magnetic declination to convert the magnetic bearing into a true bearing. Source: Internet
Computerized sources, on the other hand, are able to calculate the right ascension and declination of the "epoch of date" to the exact instant of observation. Source: Internet
But in AD 18000 or BC 8000 Crux will be/was less than 30 degrees south declination making it visible in Northern Europe. Source: Internet
A negative value for proper motion in RA indicates the sky motion is east to west, in declination north to south. Source: Internet
Determining latitude was relatively easy in that it could be found from the altitude of the sun at noon with the aid of a table giving the sun's declination for the day. Source: Internet