spheroid
volume formed by rotating an ellipse around one of its axes; special case of ellipsoid
geoid
irregular surface approximating the mean sea level
snail ball
hollow spherical housing with a viscous liquid inside
oblate spheroid
rotationally symmetric ellipsoid having a polar axis shorter than the diameter of the equatorial circle whose plane bisects it
prolate spheroid
rotationally symmetric ellipsoid having a polar axis longer than the diameter of the equatorial circle whose plane bisects it
sphere
round, rotationally symmetric shape of the 2D surface of a ball in 3D space
Earth ellipsoid
ellipsoid of rotation that approximates the figure of the Earth