Granville egg as hyperbolism of a circle
The hyperbolism of a curve c with respect to a point O a and a line d is the geometric locus of the point M defined as follows:
A point M_0 is given on c. The line OM_0 intersects d at a point P. M is the orthogonal projection of P on the line parallel to d through M_0.
See http://mathcurve.com