ellipsoid

[ ih-lip-soid ]

/ ɪˈlɪp sɔɪd /

noun

Geometry. a solid figure all plane sections of which are ellipses or circles. Typical equation: (x2/a2) + (y2/b2) + (z2/c2) = 1.

adjective

ellipsoidal.

Nearby words

Origin of ellipsoid

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

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for ellipsoid

Ellipsoid, a surface bearing the same sort of relation to a spherical surface as an ellipse bears to a circle.
The New Gresham Encyclopedia|Various
If the medullary shell be ellipsoidal, the main axis of the ellipsoid is the same as in the cortical shell.
Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia)|Ernst Haeckel
The acorn is ellipsoid, small and enclosed in a deep cup, whose scales are closely appressed.
Forest Trees of Illinois|Fuller George D.
The ellipsoid shrank to a sphere, the sphere grew a protuberance which separated and became a single bar-like cylinder.
Invaders from the Infinite|John Wood Campbell

Sporangia globose or ovoid to ellipsoid or oblong, erect or sometimes inclined or even nodding.
The Myxomycetes of the Miami Valley, Ohio|A. P. Morgan

British Dictionary definitions for ellipsoid

ellipsoid

/ (ɪˈlɪpsɔɪd) /

noun

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
a solid having this shapethe earth is an ellipsoid

Derived Formsellipsoidal (ɪlɪpˈsɔɪdəl, ˌɛl-), adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for ellipsoid

ellipsoid

1721; see ellipse + -oid. From 1861 as an adjective (earlier adjective was ellipsoidal).

Science definitions for ellipsoid

ellipsoid

[ ĭ-lĭp′soid′ ]

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.