A rotational ellipdoid is an ellipsoid that has one (in the case of a spheroid) or an infinite number (in the case of a sphere) axes of rotational symmetric.
Rotational Ellipsoid
See also
Ellipsoid, Oblate Spheroid, Sphere, SpheroidExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Rotational Ellipsoid." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/RotationalEllipsoid.html