An equinox is one of the two days in the year when day and night are of equal length.
In the Chinese calendar, the Spring Equinox always occurs in the second month.
equinox in British English
(ˈiːkwɪˌnɒks, ˈɛkwɪˌnɒks)
noun
1.
either of the two occasions, six months apart, when day and night are of equal length
vernal equinox, autumnal equinox
2. another name for equinoctial point
Word origin
C14: from Medieval Latin equinoxium, changed from Latin aequinoctium, from aequi-equi- + nox night
equinox in American English
(ˈikwɪˌnɑks; ˈɛkwənɑks)
noun
1.
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 vernal equinox occurs about March 21 and marks the beginning of spring, and the autumnal equinox occurs about September 22 and marks the beginning of autumn
2.
either of the two points on the celestial sphere where the sun's path crosses the celestial equator
: also called equinoctial point
Word origin
ME < OFr equinoxe < ML aequinoxium < L aequinoctium < aequus (see equal) + nox, night
Examples of 'equinox' in a sentence
equinox
There was a belief for a long time that the equinox - when there are roughly equal hours of day and night - affects the weather.
Times, Sunday Times (2016)
And it's nothing to do with solstice or equinox ,' said Oriole, `because the exact solstice is tomorrow.
Fay Weldon NOTHING TO WEAR AND NOWHERE TO HIDE: A COLLECTION OF SHORT STORIES (2001)
She had saved it for tonight, the autumn equinox, although she was not quite sure why.