Biology. the gradual change in certain characteristics exhibited by members of a series of adjacent populations of organisms of the same species.
Linguistics. (in systemic linguistics) a scale of continuous gradation; continuum.
1935–40; < Greek klī́nein to lean 1
In biology, a cline is a gradual change in a trait or characteristic across a population of a species. This gradient occurs over a geographic area where environmental factors, such as altitude or temperature, vary. One example of a cline is the variation in zebra stripes across Africa. In the North, zebras have bold, black-and-white stripes over their entire bodies. Moving south, the stripes become fainter and more brownish-gray. In the most southern regions, their stripes are even more faded, and the lower legs are solid white. In a cline, there is no abrupt, sudden change; rather, traits change gradually across a spectrum based on the animal's geographic range.
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Alternatively, flowering plants tend to bloom at different times depending on where they are along the slope of a mountain, known as an altitudinal cline.
From Textbooks ● Jun. 9, 2022
One type of geographic variation, called a cline, can be seen as populations of a given species vary gradually across an ecological gradient.
From Textbooks ● Jun. 9, 2022
Using other databases, researchers had found that the number of genes that contribute to tallness in Europeans increased on a cline from south to north.
From Science Magazine ● Jan. 3, 2019
Therefore, the observation of an Africa-based phoneme inventory cline does not generalize to other linguistic characteristics of a similar kind.
From Science Magazine ● Feb. 9, 2012
There seems to be a cline from paler snakes having fewer stripes in the north to darker snakes in the south.
From A Revision of Snakes of the Genus Conophis (Family Colubridae, from Middle America) by Wellman, John
Apa's famous friends left apparent messages of support under his post, including his Map That Leads to You co-star Madelyn Cline, who wrote: "Identify theft is not a joke."
From BBC ● May 7, 2026
The site is the second-largest gas field in the world, according to British energy consultancy Gaffney, Cline and Associates, behind only South Pars, shared by Iran and Qatar.
From Barron's ● Apr. 21, 2026
This sentimental and self-indulgent social-dance affair to musical selections from Antonín Dvořák, Patsy Cline, Billy Joel, Stevie Wonder and Donna Summer goes nowhere, repeatedly.
From The Wall Street Journal ● Nov. 17, 2025
Cinematographer Bianca Cline took over as director of photography when production resumed in Montana about 18 months after Hutchins’ death.
From Los Angeles Times ● May 1, 2025
“Those things we’ve been worrying about,” Cline said, “it looks as though we’ve really got something.”
From "Fallout: Spies, Superbombs, and the Ultimate Cold War Showdown" by Steve Sheinkin
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
