ŏc'ta-hē'dron, n.

n. [Gr. ὀκτάεδρον, from ὀκτάεδρος, eight-sided, from ὀκτώ, eight, and ἕδρα, seat, base, from ἕζεσθαι, to sit; L. octaedrum, Sp. octaedro, It. ottaedro.] (Geom.) A solid contained by eight equal and equilateral triangles.