Source : Webster's Revised Unabridged Dictionary (1913)

Colure \Co*lure"\, n.; pl. {Colures}. [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.