kəˈlu̇(ə)r, ˈkōˌl- noun
( -s )
Etymology: Late Latin coluri, plural, from Greek kolouroi colures, plural of kolouros stump-tailed, from kol- (from kolos docked) + -ouros -urous; from the fact that in temperate latitudes a part is always below the horizon — more at halt
: a great circle on the celestial sphere passing through the poles and the equinoxes or the solstices