diurnal

Etymology

It is inherited from Middle English diurnal,^[2][3][4] borrowed from Late Latin diurnālis (“daily”),^[5][3][6][7] from Latin diurnus (“daily”),^[3][8][7] from diēs (“day”),^[3][8][9] from Proto-Indo-European *dyeu- (“to shine”).^[6][3] The Latin ending is the adjectival suffix -urnus, denoting time,^[6][8] and Barnhart takes diurnus as modelled on nocturnus (“by night”).^[5] Klein compares hibernus (“wintry”) and derives the suffix from a form related to the ending of Ancient Greek χειμερινός (kheimerinós, “wintry”).^[8] The root also gives Welsh diw, Breton deiz, Lithuanian diena and Polish dzień, all meaning day.^[6] Journal is a doublet of diurnal,^[5][8] and journey goes back to a noun use of diurnus.^[10]

Earliest recorded meaning

Daily, of the motion of the heavens: about 1390, in Chaucer's Man of Law's Tale, thy diurnal sweigh, his only use of the word.^[2][5][11] The OED begins with Lydgate about 1430,^[12] and Dictionary.com with 1400–50.^[13]

Semantic evolution

The word began as a term of astronomy,^[14][12] for the movement of the heavenly bodies in the space of a day: Lydgate uses it of the arc and courses of the sun and stars.^[2] A wider sense, belonging to every day, is recorded from 1594 in the OED,^[12] although Etymonline and the MED have it earlier.^[6][2] Cockeram's dictionary of 1623 first records the sense of the day as against the night,^[12][6] and this later became the zoologist's term for animals active by day, the sense that the Shorter Oxford dates only to the late 19th century.^[7][12] The noun followed the same sense of daily: a service book of the day hours (before 1550), a day-book or diary (1589) and a daily or periodical newspaper (before 1645).^[12][7] Weekley notes that diurnal was often used for journal in the 17th century, and quotes the preface to Blount's Glossographia of 1656.^[15] Johnson (1755) gave both the day-related adjective, with Milton, and the noun as a journal or day-book.^[16]

Timeline

• c. 1390 – occurring every day, of the daily motion of the heavens.^[2][5]
• c. 1430 – performed in or occupying one day, chiefly of the heavenly bodies.^[12]
• before 1550 – noun, a service book of the day hours.^[12]
• 1589 – noun, a day-book, diary.^[12]
• 1594 – recurring every day; of periodicals, published daily.^[12]
• 1623 – of the day as opposed to the night; of animals, active by day.^[12][6]
• before 1645 – noun, a daily newspaper.^[12]
• 1866 – lasting for a day only.^[12]

Meanings

Adjective

1. Recurring every day; having a daily cycle: Tides and temperatures in the bay follow a diurnal pattern.^[4][7][14]
2. Of or during the daytime, as against the night; opposed to nocturnal.^[14][4][12]
3. (zoology) Of animals, active mainly by day.^[14][4][17]
4. (botany) Of flowers, open during the day and closed at night.^[14][17]
5. (astronomy) Performed in or occupying one day, or resulting from the daily rotation of the earth.^[14][7][12]
6. (rare) Lasting for a day only; ephemeral.^[12]

Noun

1. A service book containing the day hours, without matins.^[17][12][4]
2. (archaic) A diary or day-book.^[4][12][7]
3. (archaic) A daily newspaper or journal.^[4][12][7]

Word family

• diurnally
• diurnalness
• semidiurnal
• undiurnal
• diurnal arc
• diurnal motion

Related words

• journal
• journey
• adjourn
• sojourn
• nocturnal

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e 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 The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
6. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ a b c d e f g h Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
8. ^ a b c d e Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
10. ^ Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
11. ^ Benson, Larry D., Glossarial Concordance to Middle English (Chaucer, Gower), Johns Hopkins University, github.com/jhu-digital-manuscripts/gcme
12. ^ a b c d e f g h i j k l m n o p q r s Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
13. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
14. ^ a b c d e f Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
15. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
16. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
17. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins