different between elliptical vs ellipsoid

English

Etymology

elliptic +? -al, from Ancient Greek ??????????? (elleiptikós), from ??????? (elleíp?, “I leave out, omit”). Surface analysis ellipse +? -ical.

Pronunciation

• (UK) IPA^(key): /??l?p.t?k.?l/
• (US) IPA^(key): /??l?p.t?.k?l/, /??l?p.t?.k?l/

Adjective

elliptical (comparative more elliptical, superlative most elliptical)

1. In a shape of, or reminding of, an ellipse; oval.
   • 1876, Edward Roth (translator), All Around the Moon, Chapter XIX,

     Having admitted that the projectile was describing an orbit around the moon, this orbit must necessarily be elliptical; science proves that it must be so.

2. Of, or showing ellipsis; having a word or words omitted.

   If he is sometimes elliptical and obscure, it is because he has so much to tell us. -- Edmund Wilson

3. (of speech) Concise, condensed.
   • 1903, Gilbert Keith Chesterton, Robert Browning, Chapter VI,

     Browning's dark and elliptical mode of speech, like his love of the grotesque, was simply a characteristic of his, a trick of his temperament, and had little or nothing to do with whether what he was expressing was profound or superficial.

   • early XX c., The Making of a New Yorker, by O. Henry

     He was called a tramp; but that was only an elliptical way of saying that he was a philosopher, an artist, a traveller, a naturalist and a discoverer.

4. (mathematics, rare) Elliptic.

Usage notes

• In botanical usage, elliptic(al) refers only to the general shape of the object (usually a leaf), independently of its apex or margin (and sometimes the base), so that an "elliptic leaf" may very well be pointed at both ends. A three-dimensional elliptical object is ellipsoid, while an object that is not a perfectly stretched circle is ovoid or obovoid.

Synonyms

• elliptic

Translations

Noun

elliptical (plural ellipticals)

1. (astronomy) An elliptical galaxy.
2. An elliptical trainer.

Translations

English

Etymology

ellipse +? -oid

Noun

ellipsoid (plural ellipsoids)

1. (mathematics, geometry) A surface, all of whose cross sections are elliptic or circular (including the sphere), that generalises the ellipse and in Cartesian coordinates (x, y, z) is a quadric with equation x²/a² + y²/b² + z²/c² = 0.
   • 2002, John Michael Hollas, Basic Atomic and Molecular Spectroscopy, page 133,

     Polarizability can be imagined as a three-dimensional ellipsoid centred on the centre of the molecule, as shown in Figure 10.4.

   • 2004, Alfred Leick, GPS Satellite Surveying, 3rd Edition, page 367,

     Because only ellipsoids of rotation have been adopted in practical geodesy and surveying and triaxial ellipsoids have been limited to theoretical studies, we will use the term ellipsoid for brevity to mean ellipsoid of rotation.

   • 2010, Jan Van Sickle, Basic GIS Coordinates, 2nd Edition, page 73,

     As mentioned before, modern geodetic datums rely on the surfaces of geocentric ellipsoids to approximate the surface of the earth.

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

Usage notes

The general case, with semiaxes a, b and c all different, is a triaxial ellipsoid (more rarely, scalene ellipsoid). If two are the same, say b = c, the result is an ellipsoid of revolution, which may be oblate (if a < b) or prolate (a > b). The degenerate case a = b = c is a sphere. An ellipsoid of revolution is also called a spheroid.

Hypernyms

• quadric surface, quadric

Derived terms

• ellipsoid of revolution
• ellipsoid geodesic
• ellipsoid method
• ellipsoid packing
• scalene ellipsoid (rare)
• triaxial ellipsoid

Related terms

• ellipsoidal
• subellipsoid

Translations

See also

• geoid

Adjective

ellipsoid (comparative more ellipsoid, superlative most ellipsoid)

1. Shaped like an ellipse; elliptical.
2. (mathematics) Of or pertaining to an ellipse; elliptic.
3. (botany) Having the tridimensional shape of an ellipse rotated on its long axis.

Related terms

• ellipsoidal
• globoid
• ovoid

Translations

See also

• globose
• oblong

Swedish

Noun

ellipsoid c

1. (mathematics) ellipsoid

Declension