n. [ Gr. &unr_; eight-cornered; 'okta- (for 'oktw` eight) + &unr_; an angle: cf. F. cctogone. ] 1. (Geom.) A plane figure of eight sides and eight angles. [ 1913 Webster ]
2. Any structure (as a fortification) or place with eight sides or angles. [ 1913 Webster ]
Regular octagon, one in which the sides are all equal, and the angles also are all equal. [ 1913 Webster ]