aequinoctium

Forms

aequinoctium n (genitive aequinoctiī or aequinoctī); second declension^[1]

Etymology

It is from Latin aequus (“equal”) + nox (“night”) + -ium, the time when night is equal to day.^[2][3][4][1] De Vaan lists it among the derivatives of nox, from Cato on;^[5] for aequus he finds no convincing etymology.^[5]

Varro already explained the name: when the sun comes midway between the winter and the summer solstice, day becomes equal to night, hence the name;^[3] Isidore of Seville repeats the explanation.^[3]

Earliest recorded meaning

De Vaan and Gaffiot date it from Cato,^[5][6] whose treatise on agriculture uses aequinoctium vernum, the spring equinox, to date farm work.^[3]

Semantic evolution

It names each of the two equinoxes, the time or season of the equinox.^[2] Writers distinguish the aequinoctium vernum (or vernale) from the aequinoctium autumnale (or autumni), and Isidore dates them to the eighth day before the Kalends of April and of October.^[3] Cicero and Caesar use it,^[4][6] Livy has both the spring and the autumn equinox,^[4] and Pliny the Elder says that the tides swell most at the two equinoxes, more at the autumnal than at the vernal.^[4][3]

Medieval writers in Britain use it for the equinox, and an English record of 1233 dates a payment by the equinox of Saint Michael, the autumnal equinox.^[7] English took it as equinox about 1400, from Old French or from Medieval Latin.^[8]

Timeline

• 234–149 BC – Cato uses aequinoctium vernum in his treatise on agriculture.^[3][9]
• 116–27 BC – Varro explains the name from day and night being equal.^[3][9]
• c. 50 BC – Caesar uses it.^[4][9]
• 23/24–79 AD – Pliny the Elder writes that the tides are highest at the equinoxes.^[4][9]
• c. 560–636 AD – Isidore of Seville dates the two equinoxes.^[3][9]
• 1233 – An English record names the autumnal equinox after Saint Michael.^[7]
• c. 1400 – Borrowed into English as equinox.^[8]

Meanings

Noun

1. An equinox; the time or season of the equinox (often in the plural, the two equinoxes).^[2][4][10]
2. aequinoctium vernum, autumnale: the spring and the autumn equinox.^[3][4]

Word family

• aequinoctiālis

Related words

• aequus
• nox
• English equinox

References

1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
3. ^ a b c d e f g h i j Thesaurus linguae Latinae (1900–), Leipzig: Teubner; Berlin: De Gruyter; open-access ed., Munich: Bayerische Akademie der Wissenschaften
4. ^ a b c d e f g h Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
5. ^ a b c de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill
6. ^ a b Gaffiot, Félix (2016), Dictionnaire latin-français, new ed. by Gérard Gréco et al. (Gaffiot 2016), online ed.
7. ^ a b Latham, R. E., D. R. Howlett, R. K. Ashdowne, et al. (1975–2013), Dictionary of Medieval Latin from British Sources, London: British Academy / Oxford University Press
8. ^ a b Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
9. ^ a b c d e Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de
10. ^ Stelten, Leo F. (1995), Dictionary of Ecclesiastical Latin, Peabody, Mass.: Hendrickson