Translation guide
An octagon is an eight-sided polygon. In Japanese, the most common term is 八角形 (hakkakkei), used in geometry and everyday contexts. The word 八角形 can also refer to octagonal shapes in architecture or design. For specialized contexts like martial arts rings, the loanword オクタゴン (okutagon) is used.
Referring to an eight-sided polygon in mathematics, design, or general description.
Referring to the octagonal fighting area in sports like MMA.
Loanword from English, specifically used for the UFC octagon or similar fighting rings. Not used for geometric shapes.
The fighter entered the octagon.
I bought an octagonal table.
この建物は八角の塔がある。
This building has an octagonal tower.