octagonal
Americanadjective
adjective
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having eight sides and eight angles
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of or relating to an octagon
Other Word Forms
Etymology
Origin of octagonal
1565–75; octagon + -al 1, replacing earlier octogonal < New Latin octōgōnālis, equivalent to octō- octo- + Greek gōn ( ía ) angle + -ālis -al 1
Explanation
Anything that's octagonal has eight sides and eight angles. A stop sign has an octagonal shape, and so may your trampoline You can also call something that's octagonal an octagon. Octagonal buildings may be unusual, but you can find examples of them around the world — there are many churches and cathedrals with octagonal sections, for example. Both octagonal and octagon come from the Greek oktagononos, "eight-angled," from the roots okto, "eight," and gonia, "angle."
Vocabulary lists containing octagonal
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The Monticello we know today presents itself as a compact unity, prefaced by a classical temple front and crowned by an octagonal dome—the first domed house in America.
From The Wall Street Journal ● Jun. 19, 2026
The temporary arena that has been under construction is slated to feature an octagonal cage for the fights at its center, and it’s expected to fit about 4,000 guests.
From MarketWatch ● May 29, 2026
The gothic building with its octagonal tower was once home to Hammer Horror Studios.
From BBC ● Oct. 30, 2025
There’s dark woodwork, octagonal pillars, curlicues of ironwork in the old-fashioned windows, carved details of garlands and flowers and urns.
From Seattle Times ● Feb. 15, 2024
All mitered cuts because, he announced, The Amazing Deck would be octagonal.
From "Please Ignore Vera Dietz" by A.S. King
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
