Co‐lure″ (?), n.; pl.Colures (#). [F. colure, L. coluri, pl., fr. Gr. κόλουροσ dock-tailed, αἱ κόλουροι (sc. γραμμαί lines) the colures; fr. κόλοσ docked, stunted + ουρἄ 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° 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.