(n.) A curve formed by a section of a cone, when the cutting plane makes a greater angle with the base than the side of the cone makes. It is a plane curve such that the difference of the distances from any point of it to two fixed points, called foci, is equal to a given distance. See which is also an hyperbola Both curves are regarded as branches of the same hyperbola See.

arc bow catacaustic catenary caustic circle conchoid crook curl curve diacaustic ellipse festoon hook lituus parabola sinus tracery