ellipsoid

[ ih-lip-soid ]

noun

1. Geometry. a solid figure all plane sections of which are ellipses or circles. Typical equation: ( x 2 / a 2 ) + ( y 2 / b 2 ) + ( z 2 / c 2 ) = 1.

adjective

1. ellipsoidal.

ellipsoid

/ ɪˈlɪpsɔɪd; ɪlɪpˈsɔɪdəl; ˌɛl- /

noun

1. 1. a geometric surface, symmetrical about the three coordinate axes, whose plane sections are ellipses or circles. Standard equation: x ²/ a ² + y ²/ b ² + z ²/ c ² = 1, where ± a , ± b , ± c are the intercepts on the x-, y-, and z- axes
   2. a solid having this shape

      the earth is an ellipsoid

ellipsoid

/ ĭ-lĭp′soid′ /

1. A three-dimensional geometric figure resembling a flattened sphere. Any cross section of an ellipsoid is an ellipse or circle. An ellipsoid is generated by rotating an ellipse around one of its axes.

Derived Forms

• ellipsoidal, adjective

Word History and Origins

Origin of ellipsoid¹

From the French word ellipsoïde, dating back to 1715–25. See ellipse, -oid

Example Sentences

Its form is that of an ellipsoid, with a major axis 26 millimetres in length, while the minor axis measures 11 millimetres.

From Project Gutenberg

Ellipsoid, a surface bearing the same sort of relation to a spherical surface as an ellipse bears to a circle.

From Project Gutenberg

We shall so select the law of contraction that the point S may be at the focus of the meridian section of the ellipsoid.

From Project Gutenberg

If therefore a little hump were discovered on the terrestrial ellipsoid, this discovery would be by itself of no great interest.

From Project Gutenberg

The roof was the long half of an ellipsoid, and the opening in it was over one of the foci of the ellipse of the floor.

From Project Gutenberg