(1):

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

(2):

(n.) The act or state of declining or refusing; withdrawal; refusal; averseness.

(3):

(n.) The act or state of bending downward; inclination; as, declination of the head.

(4):

(n.) The act of inflecting a word; declension. See Decline, v. t., 4.

(5):

(n.) The act of deviating or turning aside; oblique motion; obliquity; withdrawal.

(6):

(n.) 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.

(7):

(n.) The angular distance of any object from the celestial equator, either northward or southward.