# ellipse

[ ih-lips ]
See synonyms for: ellipseellipses on Thesaurus.com

nounGeometry.
1. a plane curve such that the sums of the distances of each point in its periphery from two fixed points, the foci, are equal. It is a conic section formed by the intersection of a right circular cone by a plane that cuts the axis and the surface of the cone. Typical equation: (x2/a2) + (y2/b2) = 1. If a = b the ellipse is a circle.

## Origin of ellipse

1
First recorded in 1745–55; from French, from Latin ellīpsis ellipsis; or by back formation from the plural ellipses

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

## How to use ellipse in a sentence

• You were perfect until the very end of that last sentence, when you unaccountably used ellipses instead of a period!

Ben Yagoda: How I Not Write Bad | Noah Charney | February 13, 2013 | THE DAILY BEAST
• In Figures 76 and 77 are a series of ellipses marked with pins and a piece of twine, as already described.

• Ellipses match the original except in poetry quotations where a short line represents an ellipses.

The Astronomy of the Bible | E. Walter Maunder
• There is a tendency to confine the asterisk to such cases, and to use the full stop for shorter ellipses.

"Stops" | Paul Allardyce
• Dave Cowan ceased to draw angled designs on his pad; he now drew circles, ovals, ellipses, things fluent with curves.

The Wrong Twin | Harry Leon Wilson
• Long stretches of periods have been normalized to regular ellipses.

The Katipunan | J. Brecknock Watson (AKA Francis St. Clair)

## British Dictionary definitions for ellipse

ellipse

/ (ɪˈlɪps) /

noun
1. a closed conic section shaped like a flattened circle and formed by an inclined plane that does not cut the base of the cone. Standard equation x ²/ a ² + y ²/ b ² = 1, where 2 a and 2 b are the lengths of the major and minor axes. Area: π ab

## Origin of ellipse

1
C18: back formation from ellipsis

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

## Scientific definitions for ellipse

ellipse

[ ĭ-lĭps ]

1. A closed, symmetric curve shaped like an oval, which can be formed by intersecting a cone with a plane that is not parallel or perpendicular to the cone's base. The sum of the distances of any point on an ellipse from two fixed points (called the foci) remains constant no matter where the point is on the curve.

## Cultural definitions for ellipse

ellipse

[ (i-lips) ]

In geometry, a curve traced out by a point that is required to move so that the sum of its distances from two fixed points (called foci) remains constant. If the foci are identical with each other, the ellipse is a circle; if the two foci are distinct from each other, the ellipse looks like a squashed or elongated circle.

## Notes for ellipse

The orbits of the planets and of many comets are ellipses.