Oc"ta*gon (?), n. [Gr. eight-cornered; (for eight) + an angle: cf.F. cctogone.]
1. Geom.
A plane figure of eight sides and eight angles.
2.
Any structure (as a fortification) or place with eight sides or angles.
Regular octagon, one in which the sides are all equal, and the angles also are all equal.
© Webster 1913.