Trisoctahedron n. (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.