Equinox
English Meaning
The time when the sun enters one of the equinoctial points, that is, about March 21 and September 22. See Autumnal equinox, Vernal equinox, under Autumnal and Vernal.
- Either of two points on the celestial sphere at which the ecliptic intersects the celestial equator.
- Either of the two times during a year when the sun crosses the celestial equator and when the length of day and night are approximately equal; the vernal equinox or the autumnal equinox.