https://www.merriam-webster.com/dictionary/equinoctial%20colure
EQUINOCTIAL COLURE Definition & Meaning - Merriam-Webster
The meaning of EQUINOCTIAL COLURE is the circle of 0 and 12 hours right ascension passing through the equinoctial points of the celestial sphere.
equinoctial coluredefinitionmeaningmerriamwebster