Definition of equinox in English:

equinox

Pronunciation: /ˈēkwəˌnäks//ˈekwəˌnäks/

noun

  • 1The time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length (about September 22 and March 20)

    • ‘Day is slightly longer than night at the equinoxes.’
    • ‘It lies close to the date midway between an equinox and a solstice. Such dates carry an importance in many European and European-derived calendars.’
    • ‘It was once connected with the fall equinox, the day when day and night are equal.’
    • ‘He relied on the formula adopted by the Church two centuries before, the Easter shall fall on the first Sunday after the first full moon after the spring of the equinox.’
    • ‘The lengths of the hours were equal around the equinoxes but the rest of the time they could vary considerably.’
    • ‘The rapidly changing length of day around the equinoxes might disturb the circadian and sleep-wake rhythms and change mood and activity in vulnerable individuals.’
    • ‘Long-term changes in the dates of the solstices and equinoxes are caused mainly by tugs imposed on the orientation of the Earth's spin axis by the Moon.’
    • ‘These nine nights occur on equinoxes or equal nights when the sun is vertically overhead at the equator or centre.’
    • ‘It won't be until after the equinox on 23 September that the longer days will allow the warmth to settle in.’
    • ‘As a result, the actual occurrence of the equinoxes and solstices slowly moved away from their calendar dates.’
    • ‘What was left of the population had to cross the equator every equinox to escape the now-extreme winters and summers.’
    • ‘At this stage we might as well mention two other very important dates in the year, the equinoxes.’
    • ‘Others (like astronomers) may insist that the equinoxes and solstices mark the season starts, so that spring begins with the vernal or spring equinox around March 20.’
    • ‘‘An equinox is when night and day are equal,’ he said.’
    • ‘Anyone who says day and night is equal on the equinox hasn't bothered to let facts get in the way of theory.’
    • ‘The Harvest Moon, therefore, occurs within several days of September 23, the fall equinox.’
    • ‘Note that day length is at a minimum at the start of winter, at a maximum at the start of summer, and is 12 hours at the spring and fall equinoxes.’
    • ‘I feel a strong attachment to the equinox in March because my birthday is the 23rd and so I usually try to combine a celebration of the two.’
    • ‘Technically, a solstice is an astronomical point and, due to the procession to the equinox, the date may vary by a few days depending on the year.’
    • ‘During the spring and fall equinoxes, the Sun also passes through this plane (from the perspective of Earth).’
    1. 1.1
      another term for equinoctial point
      • ‘The position of the stars should not be related to the point of the equinox, that is to the position of the point which changes position in the course of time, but the position of the point of the equinox should be related to the sphere of stars.’
      • ‘A tropical year is the time it takes the sun to pass from one equinox, or tropic, to the same tropic or equinox again.’

Origin

Late Middle English: from Old French equinoxe or Latin aequinoctium, from aequi- equal + nox, noct- night.

Pronunciation:

equinox

/ˈēkwəˌnäks//ˈekwəˌnäks/