Colure

Colure Kolur or "cut off" from the Greek κόλουρος, today is the obsolete term for two distinct great circles on the celestial sphere passing through the celestial poles, similar to meridian of the earth. Partially understood put up with the four meridians as Kolure. The term is meant to go back to the fact that the circles as the other spheres of heaven are not by rotation fully visible, but "cut off" by the horizon appear.