cline

noun

1. A gradation in a character or phenotype within a species, deme, or other systematic group.
2. Any graduated continuum.

   “This account effectively reconstructs the well-known grammaticalisation cline from anaphora to agreement, …”

3. A generalized circle.

   “Let C₁ and C₂ be two nonintersecting clines. Prove that there is a unique pair of points that are simultaneously symmetric to both C₁ and C₂.”

   “To visualize Möbius transformations, it is helpful to focus on fixed points and, in the case of two fixed points, on two families of clines with respect to these points.”

name

1. A surname.