### Definition of Ellipsoid

1. Noun. A surface whose plane sections are all ellipses or circles. "The Earth is an ellipsoid"

Generic synonyms: Plane Figure, Two-dimensional Figure
Derivative terms: Ellipsoidal

2. Adjective. Having the nature or shape of an ellipsoid.
Exact synonyms: Ellipsoidal, Spheroidal
Similar to: Rounded
Derivative terms: Spheroid

### Definition of Ellipsoid

1. n. A solid, all plane sections of which are ellipses or circles. See Conoid, n., 2 (a).

2. a. Pertaining to, or shaped like, an ellipsoid; as, ellipsoid or ellipsoidal form.

### Definition of Ellipsoid

1. Noun. (mathematics) a surface, all of whose cross sections are elliptic or circular (includes the sphere) ¹

2. Noun. (geography) Such a surface used as a model of the shape of the earth. ¹

3. Adjective. (mathematics) of or pertaining to an ellipse; ellipsoidal ¹

4. Adjective. Shaped like an ellipse; elliptical. ¹

5. Adjective. Shaped like a symmetrical oval that is evenly tapered on both ends. ¹

¹ Source: wiktionary.com

1. [n -S]

### Medical Definition of Ellipsoid

1. A solid, all plane sections of which are ellipses or circles. See Conoid, 2 . 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. Origin: Ellipse: cf. F. Ellipsoide. Source: Websters Dictionary (01 Mar 1998)

### Ellipsoid Pictures

Click the following link to bring up a new window with an automated collection of images related to the term: Ellipsoid Images

### Literary usage of Ellipsoid

Below you will find example usage of this term as found in modern and/or classical literature:

1. The Collected Mathematical Papers of Arthur Cayley by Arthur Cayley (1889)
"Consider the attracting ellipsoid, which for distinction may be termed the ... Legendre shows that the attraction of the portion of the ellipsoid S included ..."

2. Mathematical Crystallography and the Theory of Groups of Movements by Harold Hilton (1903)
"7} Hence — = the length of the radius vector of the ellipsoid 1 .... (iii), drawn from the centre parallel to the straight line representing B. Since this ..."

3. The Encyclopaedia Britannica: A Dictionary of Arts, Sciences, and General by Thomas Spencer Baynes (1888)
"When two only of tbe changea of length are equal, the ellipsoid becomes one of rotation, oblate or prolate as the case may be; and if the radius of the ..."

4. Manual of Petrographic Methods by Albert Johannsen (1918)
"Fresnel's ellipsoid. — The Fresnel ellipsoid is a simple ellipsoid of one surface which has for its three axes the maximum, minimum, and mean ease of ..."

5. Mathematical Papers by William Kingdon Clifford (1882)
"GEOMETRY ON AN ellipsoid*. THE metric properties of an ellipsoid are entirely ... To represent the ellipsoid on a plane we require also two fixed points ..."

6. Manual of Petrographic Methods by Albert Johannsen (1918)
"The Fresnel ellipsoid is a simple ellipsoid of one surface which has for its three axes the maximum, minimum, and mean ease of vibration. ..."