octagon
Americannoun
noun
Etymology
Origin of octagon
1650–60; < Latin octagōnon < Greek oktágōnon, noun use of neuter of oktágōnos octangular; see octa-, -gon
Explanation
An octagon is a shape with eight sides. Picture a stop sign, and you'll get the idea. If your house is a strange, roundish shape with eight walls, it's an octagon, and if your medal for being the most improved bowler in your league has a shape with eight equal sides, it's also an octagon. You'll come across the word most often in geometry class, where you'll also learn that an octagon's eight interior angles always add up to 1080 degrees. The Greek root is oktagononos, "eight-angled," from okto, "eight," and gonia, "angle."
Vocabulary lists containing octagon
Geometry - Introductory
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UCPS 6th Grade Roots List #6
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Geometry (Base List)
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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.
Another potential boxing opponent for the Cameroonian is MVP promoter Paul himself, who stepped into the octagon to celebrate with winners on Saturday.
From Los Angeles Times • May 17, 2026
Still, it’s better if the lidar knows the octagon is red.
From Barron's • May 4, 2026
Gane was equally annoyed at the outcome and could be seen pacing around the edge of the octagon, shaking his head, as the result was announced.
From BBC • Oct. 25, 2025
The contradictions of mixed martial arts brawler Mark Kerr can’t be contained by a ring, an octagon or a film.
From Los Angeles Times • Oct. 3, 2025
At lunch and after school they often gathered at a wooden table in the hallway that people called the hex table, even though, as Ian pointed out, it was an octagon, not a hexagon.
From "The 57 Bus" by Dashka Slater
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.
