cissoid

From Ancient Greek κισσός (kissós, “ivy”) + εἶδος (eîdos, “form, image”).

cissoid (plural cissoids)

1. (geometry) Any of a family of curves defined as the locus of a point, P, on a line from a given fixed point and intersecting two given curves, C₁ and C₂, where the distance along the line from C₁ to P remains constant and equal to the distance from P to C₂.

   The cissoid of a circle and a line is a conchoid

• cissoidal

• cisoids