equilateral

[ ee-kwuh-lat-er-uhl, ek-wuh- ]

/ ˌi kwəˈlæt ər əl, ˌɛk wə- /

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See synonyms for equilateral on Thesaurus.com

adjective

having all the sides equal: an equilateral triangle.

noun

a figure having all its sides equal.

a side equivalent, or equal, to others.

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Origin of equilateral

From the Late Latin word aequilaterālis, dating back to 1560–70. See equi-, lateral

OTHER WORDS FROM equilateral

e·qui·lat·er·al·ly, adverbnon·e·qui·lat·er·al, adjectivenon·e·qui·lat·er·al·ly, adverbsub·e·qui·lat·er·al, adjective

un·e·qui·lat·er·al, adjectiveun·e·qui·lat·er·al·ly, adverb

Words nearby equilateral

equicaloric, equid, equidistance, equidistant, equiform, equilateral, equilateral hyperbola, equilateralism, equilibrant, equilibrate, equilibrist

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use equilateral in a sentence

One way was to have three of them all on the same face, forming an equilateral triangular base.
Can You Bake The Radish Pie?|Zach Wissner-Gross|September 17, 2021|FiveThirtyEight
At this point, you could think of the crystal as two equilateral triangles connected by a common edge.
Can You Decipher The Secret Message?|Zach Wissner-Gross (riddlercolumn@gmail.com)|June 4, 2021|FiveThirtyEight
So if five of the edges had the same length — meaning the sixth edge was the only one with a potentially different length — that meant the two faces not straddled by this sixth edge were equilateral triangles.
Can You Decipher The Secret Message?|Zach Wissner-Gross (riddlercolumn@gmail.com)|June 4, 2021|FiveThirtyEight
For example, if you had three pennies in your pocket, then you could buy three strings that were each 1 cm long and form an equilateral triangle.
Can You Bake The Biggest π?|Zach Wissner-Gross|March 12, 2021|FiveThirtyEight

Three of them were flat on the ground, with their corners touching and enclosing an equilateral triangle.
Can You Guess The Mystery Word?|Zach Wissner-Gross|January 29, 2021|FiveThirtyEight
Equilateral can be read as a parable of the ways we blind ourselves through vanity, love, and greed.
The 2013 Novel of the Year Is…|Nathaniel Rich|December 30, 2013|DAILY BEAST
The Khedive of Egypt persuades himself that the success of the equilateral will silence his local political rivals.
The 2013 Novel of the Year Is…|Nathaniel Rich|December 30, 2013|DAILY BEAST
A third game was called trign, and was played by three persons, stationed at the angles of an equilateral triangle.
The Private Life of the Romans|Harold Whetstone Johnston
I mean of course by the relative pointed, the entire group of which the equilateral arch is the representative.
The Stones of Venice, Volume I (of 3)|John Ruskin
It is built in the figure of an equilateral triangle, having one of its angles pointing towards the sea.
Early Travels in Palestine|Arculf et al.
This consists of three plane mirrors so arranged that a cross-section of the three forms an equilateral triangle.
Physics|Willis Eugene Tower
My legs and thighs first formed an obtuse angle, afterwards an equilateral angle, and at length, an acute one.
Curiosities of Literature, Vol. 1 (of 3)|Isaac D'Israeli

British Dictionary definitions for equilateral

equilateral

/ (ˌiːkwɪˈlætərəl) /

adjective

having all sides of equal lengthan equilateral triangle

noun

a geometric figure having all its sides of equal length

a side that is equal in length to other sides

Derived forms of equilateral

equilaterally, adverb

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