A surface, all of whose cross sections are elliptic or circular (including the sphere), that generalises the ellipse and in Cartesian coordinates (x, y, z) is a quadric with equation x²/a² + y²/b² + z²/c² = 1.
Such a surface used as a model of the shape of the earth.
Shaped like an ellipse; elliptical.
Having the tridimensional shape of an ellipse rotated on its long axis.
Of or pertaining to an ellipse; elliptic.
A small sphere.