ecliptic

Etymology

It is inherited from Middle English ecliptik,^[2][3][4] borrowed from Medieval Latin eclīptica,^[3][5][4] short for līnea eclīptica (“the ecliptic line”),^[3][6] the feminine of Latin eclīpticus (“of an eclipse”),^[3][4][6][7] from Ancient Greek ἐκλειπτικός (ekleiptikós),^[6][7][8] from ἐκλείπω (ekleípō, “to fail to appear”),^[1][7][3] the source of eclipse,^[3][5] from ἐκ (ek, “out”) and λείπω (leípō, “to leave”),^[1][5] from Proto-Indo-European *leikw- (“to leave”).^[5][3] The OED allows that the word came directly from Latin or through French écliptique.^[8] The line was so called because eclipses can happen only when the moon is on or very near it.^[5][7][8][4]

Earliest recorded meaning

The Sun's apparent path among the stars, and the circle that shows it on an astrolabe: The ecliptik lyne of thy zodiac is the outerest bordure of thy zodiac, in Chaucer's Treatise on the Astrolabe (1391, manuscript about 1400).^[2][8] Trevisa, before 1398, wrote of the line called linia ecliptica, in the Latin form.^[2] Etymonline dates the English word to the late 14th century,^[5] and Chaucer uses it 12 times.^[9]

Semantic evolution

Early records often have the word with a noun: ecliptic line, ecliptic circle or ecliptic way, phrases the OED follows until 1712.^[8] The noun alone is recorded by the OED from 1625,^[8] though Hoad dates it to the 14th century and Merriam-Webster to the 15th.^[7][4] The Latin sense of the adjective, "of an eclipse", is recorded in English from 1609, as in ecliptic limits, the limits within which an eclipse is possible.^[8] In 1813 the name was also given to a great circle on a globe of the Earth.^[8] From 1634 the adjective occasionally appears by mistake for elliptic.^[8]

Timeline

• 1391 – ecliptik lyne, the Sun's apparent path, in Chaucer.^[2][8]
• 1609 – adjective, of or relating to an eclipse.^[8]
• 1625 – noun alone, the great circle of the Sun's apparent path.^[8]
• 1634 – adjective, used by mistake for elliptic.^[8]
• 1813 – a great circle on the terrestrial globe in the plane of the celestial one.^[8]

Meanings

Noun

1. The great circle of the celestial sphere marking the Sun's apparent path among the stars over a year; the plane of the Earth's orbit extended to meet that sphere.^[10][3][4]
2. A corresponding great circle drawn on a terrestrial globe, at an angle of about 23° to the equator.^[10][3][4]

Adjective

1. Of or relating to the ecliptic: the ecliptic plane.^[10][4]
2. Of or relating to an eclipse.^[4][8][11]

Word family

• ecliptically

Related words

• eclipse
• ellipsis

References

1. ^ a b c Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
3. ^ a b c d e f g h i The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d e f g h i Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b c Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d e Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
8. ^ a b c d e f g h i j k l m n o Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
9. ^ Benson, Larry D., Glossarial Concordance to Middle English (Chaucer, Gower), Johns Hopkins University, github.com/jhu-digital-manuscripts/gcme
10. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins
11. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press