What does octagon mean?
An octagon is a geometric figure or object with eight sides and eight angles. As a shape, it is one of the simplest regular polygons, and the word is also used for buildings, rooms, signs, and other things whose outlines follow that form. In everyday contexts, an octagon is especially familiar as the shape of stop signs, although the origin of that design is often associated with the Roman term octostilos and earlier octagonal milestones. The word comes from Greek, combining elements meaning “eight” and “angle.” “Octagonal” is the corresponding adjective, as in “an octagonal chamber” or “an octagonal plaza.” Octagons are less common than circles or squares in architecture and design, but they are distinctive because their many sides suggest both regularity and geometric precision. The word is used in both British and American English, with no major regional difference in meaning or pronunciation.
nounA geometric plane figure with eight straight sides and eight angles. The word can also refer to a building, room, or other object whose plan or form is based on this shape.
- A geometric plane figure consisting of eight straight sides and eight angles.
- A building, room, or other object with an eight-sided plan or outline.
"The town square is dominated by a grand octagon lined with cafés and historic buildings."
"The architect designed the concert hall as a large octagon."
"The sign has a red border arranged in an octagon."
The standard plural of “octagon.”
"The pattern contains several small octagons arranged in rows."
An octagon turns the familiar act of stopping into a shape: its eight sides form a traditional warning sign for drivers.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does octagon come from?
The English word “octagon” comes from the Greek ὀκτάγωνον, formed from elements meaning “eight” and “angle.” It entered English through learned usage in geometry and architecture. The same roots are reflected in the adjective “octagonal,” while related forms in other languages preserve the Greek numerical and geometric elements.
Related word forms
How octagon is actually used
In general use, “octagon” most often refers to the geometric figure or to the shape of an object. In technical geometry, it specifically denotes a polygon with eight sides. “Octagonal” is the usual adjective.