ellipse

American  

[ih-lips] / ɪˈlɪps /

noun

Geometry.

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: (x 2 / a2 ) + (y 2 / b2 ) = 1. If a = b the ellipse is a circle.

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ellipse British  

/ 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

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ellipse Scientific  

/ 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.

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ellipse Cultural  

1. 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.

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Discover More

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

Etymology

Origin of ellipse

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

Compare meaning

How does ellipse compare to similar and commonly confused words? Explore the most common comparisons:

• ellipse vs. hyperbola

Explanation

An ellipse is a closed-plane curve that results from the intersection of a plane cutting through a cone. In other words, it’s an oval. This is a word you'll probably see in geometry class, though it's a shape you can find all over the place. An ellipse is a closed curve that never made it around to a circle. If one thing travels around another in the shape of an ellipse — like the earth around the sun — it has an elliptical orbit. The plural for both ellipse and ellipsis is ellipses — so be careful not to mix up your ovals with your dots.

Example Sentences

There is also a separate viewing party on the Ellipse that could draw as many as 50,000 people, he said.

From The Wall Street Journal • Jan. 23, 2026

His address on the Ellipse was delivered as Congress was set to certify the 2020 election results for the winner, Joe Biden.

From BBC • Nov. 11, 2025

Remember Eastman's get-up on Jan. 6 when he addressed the crowd at the Ellipse near the White House, in some kind of louche cowboy hat and silk scarf?

From Salon • Jul. 22, 2023

I was meeting with Axelrod and Rozman Kendler, the export administration chief, at the Commerce Department building, in an office overlooking the Ellipse in downtown Washington, D.C.

From New York Times • Jul. 12, 2023

According to this theory, the Inner Ellipse or Horseshoe of Blue Stone was made by them, the Druids adopting it as their temple at a much later date.

From From John O'Groats to Land's End by Naylor, Robert

Related Words

• arc
• arch
• contour
• loop
• trajectory