The Collaborative International Dictionary
Ellipsoid \El*lip"soid\, n. [Ellipse + -oid: cf. F. ellipsoide.] (Geom.) A solid, all plane sections of which are ellipses or circles. See Conoid, n., 2 (a) .
Note: The ellipsoid has three principal plane sections, a, b, and c, each at right angles to the other two, and each dividing the solid into two equal and symmetrical parts. The lines of meeting of these principal sections are the axes, or principal diameters of the ellipsoid. The point where the three planes meet is the center.
Ellipsoid of revolution, a spheroid; a solid figure generated by the revolution of an ellipse about one of its axes. It is called a prolate spheroid, or prolatum, when the ellipse is revolved about the major axis, and an oblate spheroid, or oblatum, when it is revolved about the minor axis.
Wiktionary
n. (context geometry English) A spheroid; a solid of revolution generated by rotating an ellipse about one of its axis.
WordNet
n. a shape that is generated by rotating an ellipse around one of its axes; "it looked like a sphere but on closer examination I saw it was really a spheroid" [syn: spheroid]
Usage examples of "ellipsoid of revolution".
An ellipsoid of revolution is a possible shape for a solid gravitating body only up to a limiting spin rate.