Noun: equinox 'ee-kwu,nóks or 'e-kwi,nóks
- Either of two times of the year when the sun crosses the plane of the earth's equator and day and night are of equal length
"The autumn equinox marks the beginning of fall in the Northern Hemisphere"
- (astronomy) either of the two celestial points at which the celestial equator intersects the ecliptic
"The vernal equinox is one of the two equinoctial points";
- equinoctial point
Derived forms: equinoxes
Type of: celestial point, cosmic time
Encyclopedia: Equinox