The Collaborative International Dictionary
Colure \Co*lure"\ (k[-o]*l[=u]r"), n.; pl. Colures (k[-o]*l[=u]rz"). [F. colure, L. coluri, pl., fr. Gr. ko`loyros dock-tailed, a"i ko`loyroi (sc. grammai` lines) the colures; fr. ko`los docked, stunted + o'yra` tail. So named because a part is always beneath the horizon.] (Astron. & Geog.) One of two great circles intersecting at right angles in the poles of the equator. One of them passes through the equinoctial points, and hence is denominated the equinoctial colure; the other intersects the equator at the distance of 90[deg] from the former, and is called the solstitial colure.
Thrice the equinoctial line
He circled; four times crossed the car of night
From pole to pole, traversing each colure.
--Milton.
Wiktionary
n. (context astronomy English) Either of two great circles (meridians) that intersect at the poles and either the equinoxes or solstices.
Wikipedia
Colure, in astronomy, is either of the two principal meridians of the celestial sphere.
Usage examples of "colure".
A Cross like a Teutonic or Maltese one, formed by four curved lines within a circle, is also common on the Monuments, and represented the Tropics and the Colures.
Cross like Teutonic or Maltese represented the Tropics and Colures, 502-l.
They represent the equinoctial and solstitial colures, binding together the four constellations in which the sun continues to rise at the spring and autumn equinoxes and at the winter and summer solstices for epochs of just under 2200 years.
Because the polar axis and the colures form an invisible whole, the entire frame is thrown out of kilter if one part is moved.
When that happens a new Pole star with appropriate colures of its own must replace the obsolete apparatus.
Also because of the phenomenon of the precession of the equinoxes, the four points on the colures (the two equinoxes and the two solstices) will appear to drift westwards at the very slow rate of 50.
As we have already said, the most noticeable effect of the latter is that the four points on the colures which mark the two equinoxes and the two solstices on the ecliptic, will drift in clockwise direction along the great ecliptic or ‘zodiacal’ circle.
When this happens, the winter solstice point is due south, and all the other colures lock to the remaining cardinal directions.