W-curve

W-curves were first investigated by Felix Klein and Sophus Lie in 1871, who also named them.

W-curves in the real projective plane can be constructed with straightedge alone.

The 'W' stands for the German 'Wurf' – a throw – which in this context refers to a series of four points on a line.

A 1-dimensional W-curve (read: the motion of a point on a projective line) is determined by such a series.

The German "W-Kurve" sounds almost exactly like "Weg-Kurve" and the last can be translated by "path curve".