quad·​ri·​lat·​er·​al | \ ˌkwä-drə-ˈla-t(ə-)rəl How to pronounce quadrilateral (audio) \

Definition of quadrilateral

 (Entry 1 of 2)

: a polygon of four sides



Definition of quadrilateral (Entry 2 of 2)

: having four sides

Examples of quadrilateral in a Sentence

Recent Examples on the Web: Noun Mathematicians recently discovered two quadrilaterals with that property — dartlike shapes with angle ratios of 1:1:1:9 and 1:1:2:8. Quanta Magazine, "Why Mathematicians Like to Classify Things," 15 Aug. 2017 Our examples above use equilateral triangles (regular triangles), squares (regular quadrilaterals) and regular hexagons. Quanta Magazine, "The (Math) Problem With Pentagons," 11 Dec. 2017 Finally, the scientists created quadrilaterals with different combinations of vertices. Adrian Cho, Science | AAAS, "New wrinkle on origami turns designing folding structures into child’s play," 14 Oct. 2019 These presumably would have yielded more complicated configurations of objects in the sky today: triangular arrangements of galaxies, along with quadrilaterals, pentagons and other shapes. Quanta Magazine, "Cosmic Triangles Open a Window to the Origin of Time," 29 Oct. 2019 Of the more than 65,000 possible quadrilaterals, only 140 of them would fold, the researchers found. Adrian Cho, Science | AAAS, "New wrinkle on origami turns designing folding structures into child’s play," 14 Oct. 2019 However, from that lexicon of foldable quadrilaterals, the researchers could assemble much larger origamis. Adrian Cho, Science | AAAS, "New wrinkle on origami turns designing folding structures into child’s play," 14 Oct. 2019 The ancient Greeks proved that the only regular polygons that tile are triangles, quadrilaterals and hexagons (as now seen on many a bathroom floor). Quanta Magazine, "Pentagon Tiling Proof Solves Century-Old Math Problem," 11 July 2017 With Arabists like Eddy and Aramco’s government relations men urging him on, the president would attempt a bolder progression—to turn his tri-faith America into a quadrilateral. Darren Dochuk, The New Republic, "Men of God and the Genesis of the U.S.-Saudi Relationship," 17 July 2019 Recent Examples on the Web: Adjective Nestled within that quadrilateral are two lenses—a wide-angle and a telephoto—but as has always been the case with the Pixel’s camera, the software is more important than the hardware. Wired, "Here's Everything Google Announced Today," 15 Oct. 2019 In May, Japan conducted its first quadrilateral exercise with France, the U.S. and Australia in the Bay of Bengal. Washington Post, "Warship shows Japan’s determination to expand military role," 3 July 2019 The Trump administration should help further incorporate India into this emerging quadrilateral relationship between themselves, Japan, and Australia. Evan Moore, National Review, "Strengthen the U.S.–India Relationship," 1 Feb. 2018 Admiral Harris’s proposal of a quadrilateral security grouping, given at a forum hosted by the Observer Research Foundation, is certain to capture Beijing’s attention. Ellen Barry, New York Times, "What China Has Been Building in the South China Sea," 2 Mar. 2016

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

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First Known Use of quadrilateral


1650, in the meaning defined above


1656, in the meaning defined above

History and Etymology for quadrilateral


Latin quadrilaterus four-sided, from quadri- + later-, latus side

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Time Traveler for quadrilateral

Time Traveler

The first known use of quadrilateral was in 1650

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Cite this Entry

“Quadrilateral.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/quadrilateral. Accessed 8 May. 2021.

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More Definitions for quadrilateral



English Language Learners Definition of quadrilateral

geometry : a flat shape that has four sides and four angles


quad·​ri·​lat·​er·​al | \ ˌkwä-drə-ˈla-tə-rəl How to pronounce quadrilateral (audio) \

Kids Definition of quadrilateral

: a flat geometric figure of four sides and four angles


quad·​ri·​lat·​er·​al | \ ˌkwäd-rə-ˈlat-ə-rəl, -ˈla-trəl How to pronounce quadrilateral (audio) \

Medical Definition of quadrilateral

: having four sides a quadrilateral muscle

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