equinox

noun
equi·nox | \ ˈē-kwə-ˌnäks , ˈe- \

Definition of equinox 

1 : either of the two points on the celestial sphere where the celestial equator intersects the ecliptic

2 : either of the two times each year (as about March 21 and September 23) when the sun crosses the equator and day and night are everywhere on earth of approximately equal length

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equinox and the Seasons

Equinox descends from aequus, the Latin word for "equal," and nox, the Latin word for "night"—a fitting history for a word that describes days of the year when the daytime and nighttime are equal in length. In the northern hemisphere, the vernal equinox marks the first day of spring and occurs when the sun moves north across the equator. (Vernal comes from the Latin word ver, meaning "spring.") The autumnal equinox marks the first day of autumn in the northern hemisphere and occurs when the sun crosses the equator going south. In contrast, a solstice is either of the two moments in the year when the sun's apparent path is farthest north or south from the equator.

Examples of equinox in a Sentence

Recent Examples on the Web

Nowadays, thousands of people flock to Stonehenge each year to celebrate the solstices and equinoxes, many of them decked out in traditional pagan garb. Author: Justin Grieser, Anchorage Daily News, "Five things to know about the longest day of the year," 21 June 2018 The sundial shows the most exact time at the spring and autumn equinoxes. Karel Janicek, Fox News, "New role for Czech Republic TV tower: A giant sundial," 20 Apr. 2018 Technically speaking, the equinox occurs when the sun is directly in line with the equator. Brian Resnick, Vox, "Summer is for meteor showers and stargazing. Here’s how to watch.," 22 June 2018 To celebrate the spring and fall equinox, Hotel Chaco in Albuquerque, N.M., and the tour operator Heritage Inspirations are offering two-day trips to the Pueblo ruins at Chaco Canyon National Historic Park. Elaine Glusac, New York Times, "Glamping Slips Into the Mainstream," 15 June 2018 Nevertheless, what the region is witnessing Wednesday is a bona fide rarity, a post-equinox significant snowstorm, especially a daytime one. Anthony R. Wood, Philly.com, "Spring snow a rarity in Philly, but it has been worse, much worse," 21 Mar. 2018 Where to look: The best place to be is Mexico because on the equinox, the pyramid at Chichen Itza on the Yucatan Peninsula puts on a wondrous show. Brian Resnick, Vox, "Summer is for meteor showers and stargazing. Here’s how to watch.," 22 June 2018 Because the two Voyager flybys occurred near an equinox and thus returned no views of winter, this extreme coloration came as quite a surprise. Carolyn Porco, Scientific American, "Cassini at Saturn: A Retrospective," 1 Oct. 2017 Does the vernal equinox fall on the same day each year? Jennifer Earl, Fox News, "First day of spring arrives: 5 things to know about the vernal equinox," 20 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'equinox.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of equinox

14th century, in the meaning defined at sense 1

History and Etymology for equinox

Middle English, from Anglo-French or Medieval Latin; Anglo-French equinocce, from Medieval Latin equinoxium, alteration of Latin aequinoctium, from aequi- equi- + noct-, nox night — more at night

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Statistics for equinox

Last Updated

17 Sep 2018

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Time Traveler for equinox

The first known use of equinox was in the 14th century

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More Definitions for equinox

equinox

noun

English Language Learners Definition of equinox

: a day when day and night are the same length

equinox

noun
equi·nox | \ ˈē-kwə-ˌnäks , ˈe-kwə- \

Kids Definition of equinox

: either of the two times each year (as in spring around March 21 and in fall around September 23) when the sun's center crosses the equator and day and night are everywhere of equal length

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