octagon
Americannoun
-
octagons
plural
noun
Other Word Forms
Noun Inflected Forms
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.
See Examples For:
During his time out of the octagon, he observed how the division changed.
From Los Angeles Times ● Sep. 19, 2026
Troop bands playing music onstage, troops putting on military combatives exhibitions in the octagon, troops sitting, uniformed and visible, beneath the Claw to watch the spectacle in person.
From Slate ● Jun. 16, 2026
OutKick — the Fox-affiliated sports site — breathlessly covered the octagon girls’ new red, white and blue outfits, describing them as possessing “American glamour.”
From Salon ● Jun. 15, 2026
The centrepiece is the "Claw" - a 92ft high metal structure that looms over the octagon and many of the seats.
From BBC ● Jun. 14, 2026
My Austrian sniper’s rifle with its blued octagon barrel and the lovely dark walnut, cheek-fitted, schutzen stock, hung over the two beds.
From "A Farewell To Arms" by Ernest Hemingway
But borders are borders, and once Strickland has been ejected, it doesn’t take long for everyone to get back to Fan Festing at the various octagons scattered around the Ellipse.
From Slate ● Jun. 16, 2026
It's like jumping into a kaleidoscope, with constantly shifting triangles, pentagons and octagons.
From BBC ● May 25, 2025
It doesn’t talk about steering, brakes, red octagons, yellow lights.
From Washington Post ● Sep. 8, 2021
The octagons and squares in the dining room rug exuded a strong sense of character, as did the nearby studio space.
From New York Times ● Oct. 6, 2017
All the space between the mouldings and the octagons is filled with most elaborate gilt carving on a blue ground.
From Portuguese Architecture by Walter Crum Watson
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.
