Colure

Part of speech: noun (n.)

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 90º 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.