Quadruple Point

A point where a curve intersects itself along four arcs. The above plot shows the quadruple point at the Origin of the Quadrifolium $(x^2+y^2)^3-4x^2y^2=0$.

See also Double Point, Triple Point

References

Walker, R. J. Algebraic Curves. New York: Springer-Verlag, pp. 57-58, 1978.