octagonian
/ˌɒk.təˈɡəʊ.ni.ən/
Etymology
From octagon + -ian.
octagonian means relating to an octagon. Lexicurio rates it Rare gem — a strength score of 80 out of 100.
adj
- Relating to an octagon
noun
- A member of a sect who worshipped at the Octagon Chapel in Liverpool