cline

Etymology

It is borrowed from Ancient Greek κλίνω (klī́nō, “to lean, slope, bend”),^{[2][3][4][5][6]} from Proto-Indo-European *klei- (“to lean”).^[7][3] Etymonline instead calls it a back-formation from incline, or from a Latinized form of the Greek verb.^[7]

Earliest recorded meaning

A graded series of differences within a species or other group of related organisms: 1938, in an article by J. S. Huxley in Nature.^[2][4][7] Dictionary.com gives the range 1935–40.^[8]

Semantic evolution

A term of biology for gradual change across a species' range, usually along an environmental or geographic transition,^[3][4] it passed to linguistics, where the OED cites it from 1961, for a scale of continuous gradation.^[2][8] The Shorter Oxford also records a general sense, a continuum with infinitely many gradations, from the mid-20th century.^[5]

Timeline

• 1938 – in biology, a graded series of differences within a species.^[2][4][7]
• 1961 – in linguistics, a scale of continuous gradation.^[2][8]

Meanings

Noun

1. (biology) A gradual change in a character or feature across the range of a species or population, usually along an environmental or geographic transition.^[3][4][9]
2. (linguistics) A scale of continuous gradation.^[8][2]
3. Any continuum with an infinite number of gradations.^[5]

Word family

• clinal
• clinally

Related words

• client
• climate
• climax
• clinic
• lean
• incline
• decline
• recline
• -cline

Usage notes

An older verb cline, to bow or incline, recorded from before 1400 to 1499, is a separate borrowing from Old French cliner and is obsolete.^[2][7] In Shetland dialect cline meant to spread, as butter on bread, from Old Norse klína, and a Warwickshire cline meant to climb.^[10]

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
7. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ a b c d Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
9. ^ Collins English Dictionary (2023), Glasgow: HarperCollins
10. ^ Wright, Joseph, ed. (1898–1905), The English Dialect Dictionary, 6 vols., Oxford: Henry Frowde; via EDD Online 4.0, University of Innsbruck (CC BY 4.0)