ellipse

noun
el·​lipse | \ i-ˈlips How to pronounce ellipse (audio) , e- \

Definition of ellipse

1a : oval
b : a closed plane curve generated by a point moving in such a way that the sums of its distances from two fixed points is a constant : a plane section of a right circular cone that is a closed curve
2 : ellipsis

Illustration of ellipse

Illustration of ellipse

ellipse 1b: F, F' foci; P, P', P'' any point on the curve; FP + PF' = FP'' + P''F' = FP' + P'F'

The Property of an Ellipse

A closed curve consisting of points whose distances from each of two fixed points (foci) all add up to the same value is an ellipse. The midpoint between the foci is the center. One property of an ellipse is that the reflection off its boundary of a line from one focus will pass through the other. As a result, in an elliptical room, a person whispering at one focus is easily heard by someone at the other. An oval may or may not fit the definition of an ellipse.

Examples of ellipse in a Sentence

Recent Examples on the Web It’s because Earth orbits the Sun in a slight ellipse. Jamie Carter, Forbes, 3 July 2022 The final garden is laid out in an ellipse that spans the full width of the property and is home to flowering shrubs native to China, Japan, and Virginia. Victoria Johnson, ELLE Decor, 1 June 2022 There are constantly rallies on the ellipse, Bopp told the court. Aaron Navarro, CBS News, 22 Apr. 2022 This one had deformed into a long, narrow ellipse, like a flaccid rubber band. Laura Preston, The New Yorker, 28 Mar. 2022 And, over the course of each day, an ellipse of light traverses the floor and concrete walls, which were cast in corrugated iron formwork and act as sound diffusers. New York Times, 5 Jan. 2022 For context, an ellipse is just a circle that has been stretched in one direction to give it an oval shape. Sarah Wells, Popular Mechanics, 16 Aug. 2021 Essentially, just as a circle has an exact center point, an ellipse has two center or focal points. Sarah Wells, Popular Mechanics, 16 Aug. 2021 The design of the immense campus, a cylindrical tower abutted by an ellipse, is meant to represent the transition of Western civilization from centralized power to democracy. Isaac Chotiner, The New Yorker, 10 Aug. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ellipse.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of ellipse

circa 1753, in the meaning defined at sense 1a

History and Etymology for ellipse

Greek elleipsis

Learn More About ellipse

Time Traveler for ellipse

Time Traveler

The first known use of ellipse was circa 1753

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Dictionary Entries Near ellipse

Elliott

ellipse

ellipses

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Statistics for ellipse

Last Updated

13 Jul 2022

Cite this Entry

“Ellipse.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ellipse. Accessed 11 Aug. 2022.

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More Definitions for ellipse

ellipse

noun
el·​lipse | \ i-ˈlips How to pronounce ellipse (audio) \

Kids Definition of ellipse

: a shape that looks like a flattened circle

More from Merriam-Webster on ellipse

Thesaurus: All synonyms and antonyms for ellipse

Nglish: Translation of ellipse for Spanish Speakers

Britannica.com: Encyclopedia article about ellipse

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