Emily Dickinson Lexicon

OC'TA-GON, n. [Gr. οκτω, eight, and γωνια, angle.]

1. In geometry, a figure of eight sides and eight angles. When the sides and angles are equal, it is a regular octagon which may be inscribed in a circle. Harris. Encyc.
2. In fortification, a place with eight bastions. Encyc.