Ellipsoid of revolution is a term used in geometry to describe a three-dimensional shape that is formed when an ellipse is rotated around an axis. There are several synonyms or related terms for this object. The most common are oblate spheroid, prolate spheroid, and spheroid. An oblate spheroid is a type of ellipsoid where the equator is wider than the polar axis, while a prolate spheroid is the opposite, with the polar axis being longer than the equator. A spheroid is a more general term that encompasses both oblate and prolate spheroids. All these synonyms are important in various fields of study, including physics, geodesy, and astronomy, among others.