octōgōnŏs (octāgōnŏs), i, adj., = ὀκτώ-γωνία,
eight-cornered , octagonal : turris marmorea octogonos, Vitr. 1, 6, 4.— As subst.: octōgōnum , i, n., an octagon , Vitr. 1, 6, 4 al.