generalized circle

Noun

 * 1)  A circle or a line, the two being regarded as types of a single form.
 * (53-4)   $$\beta \left | \zeta \right |^2 - p\zeta - \overline{p}\overline{\zeta} + \alpha = 0$$,
 * which is a generalized circle in the ζ-plane.
 * which is a generalized circle in the ζ-plane.