lunar

Etymology

It is borrowed from Latin lūnāris (“of the moon”),^[2][3][4][5] perhaps through lunaire,^[6][7][3] from lūna (“moon”).^[2][6] The Latin noun goes back to an earlier *leuksnā, Skeat's “giver of light”,^[7][8] from the Indo-European root Proto-Indo-European *lewk- (“light, brightness”),^[6][9] which also gave lūx (“light”), lūmen (“light”) and English light.^[9][5] Merriam-Webster compares Old Church Slavonic лоуна (luna, “moon”) and Middle Irish lúan (“moon”).^[5]

Earliest recorded meaning

Crescent-shaped: probably before 1425, in a translation of Guy de Chauliac's Grande Chirurgie, according to Barnhart;^[7] the Shorter Oxford also dates this sense to late Middle English, and Etymonline to the early 15th century.^[10][3]

Semantic evolution

The sense “of or belonging to the moon” is recorded from 1626, in Francis Bacon's Sylva Sylvarum;^[2][7][3] the OED notes that it formerly often meant influenced by the moon, as the older word lunatic implies.^[2][8] Collins dates the borrowing to the 17th century and Dictionary.com to 1585–95.^[11][12] From the moon's cold light came the sense “pale, not warmly bright” in Edward Young's Night Thoughts (1742).^[2] Because alchemists called silver luna, lunar caustic (1801) is fused silver nitrate.^[2][4][13] In Arabic grammar the lunar letters (1776) are those before which the l of the article stays unchanged, named after qamar, “moon”.^[2] The space age gave lunar module (1962).^[2][11] As a noun, lunar has meant a lunar distance or observation in navigation since 1830,^[2] and in slang a look or glance, recorded in Australia from 1848^[14] and by the OED from 1906.^[2]

Timeline

• ?a1425 – crescent-shaped.^[7]
• 1626 – of or belonging to the moon.^[2][7]
• 1742 – pale, not warmly bright.^[2]
• 1776 – Arabic grammar: lunar letters.^[2]
• 1801 – of silver: lunar caustic.^[2]
• 1830 – noun: a lunar distance or observation.^[2]
• 1848 – slang noun: a look or glance.^[14]
• 1962 – relating to travel to the moon: lunar module.^[2]

Modern meaning

Adjective

1. Of, relating to or situated on the moon: lunar dust.
2. Measured by or depending on the moon's motion or phases: a lunar calendar.
3. Used in or designed for travel to the moon or on its surface.
4. Shaped like a crescent; also, pale like moonlight.
5. (chemistry, archaic) Of or containing silver.

Word family

• unlunar
• circumlunar
• cislunar
• interlunar
• lunate
• semilunar

Related words

• apolune
• lunacy
• lunatic
• lunation
• lune
• lunette
• lunisolar
• perilune
• sublunary
• superlunary
• luna
• lucid
• luminous
• light

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
5. ^ a b c Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
7. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
8. ^ a b Skeat, Walter W. (1911), A Concise Etymological Dictionary of the English Language, new ed., Oxford: Clarendon Press
9. ^ a b Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
10. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
11. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins
12. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
13. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
14. ^ a b Green, Jonathon (2010), Green's Dictionary of Slang, London: Chambers; digital ed. 2016–, https://greensdictofslang.com