Dictionary
co•lure
Pronunciation: (ku-loor', kō-, kō'loor), [key]—
n. Astron.
either of two great circles of the celestial sphere intersecting each other at the poles, one passing through both equinoxes and the other through both solstices.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.