ECLIPTIC, in astronomy, a great circle of the sphere, supposed to be drawn through the middle of the zodiac, making an angle with the equinoctial of about 23° 30', which is the sun's greatest declination; or, more strictly speaking, it is that path or way among the fixed stars, that the earth appears to describe to an eye placed in the sun. See ASTRONOMY-Index.
Some call it via Solis, "the way of the sun;" because the sun in his apparent annual motion never deviates from it, as all the other planets do more or less.