Tris*oc`ta*he"dron (?), n. [Gr. thrice + FE. octahedron.] Crystallog.
A solid of the isometric system bounded by twenty-four equal faces, three corresponding to each face of an octahedron.
Tetragonal trisoctahedron, a trisoctahedron each face of which is a quadrilateral; called also trapezohedron and icositetrahedron. -- Trigonal trisoctahedron, a trisoctahedron each face of which is an isosceles triangle.
© Webster 1913.