cline (n.)

1938, in biology, "a graded series of differences within a species," a back-formation from incline or from a Latinized form of Greek klinein "to slope, to lean" (from PIE root *klei- "to lean"). Earlier, but now obsolete, was a verb cline, from Middle English clinen "to bend, bow," from Old French cliner, from Latin clinare.

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Definitions of cline from WordNet

Cline (n.)
American geneticist who succeeded in transferring a functioning gene from one mouse to another (born in 1934);
Synonyms: Martin Cline