**Do*dec`a*he"dron** (?), n. [Gr. ; twelve + seat, bottom, base: cf. F. *dod'ecaedre*.] Geom. & Crystallog.

A solid having twelve faces.

⇒ The *regular dodecahedron* is bounded by twelve equal and regular pentagons; the pyritohedron (see Pyritohedron) is related to it; the *rhombic dodecahedron* is bounded by twelve equal rhombic faces.

© Webster 1913.