What is "icositetrahedron"

Trisoctahedron \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.

n. (context mathematics English) Any of several solids having twenty-four faces.