Variant of equinox
- the time when the sun in its apparent annual movement along the ecliptic crosses the celestial equator, making night and day of equal length in all parts of the earth: in the Northern Hemisphere the occurs about March 21 and marks the beginning of spring, and the occurs about September 22 and marks the beginning of autumn
- either of the two points on the celestial sphere where the sun's path crosses the celestial equatoralso called equinoctial point
Origin: ME < OFr equinoxe < ML aequinoxium < L aequinoctium < aequus (see equal) + nox, night
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