deltoidal icositetrahedron noun1 •A convex polyhedron that has 24 congruent kite-shaped faces and 48 edges and is a Catalan solid, being the dual polyhedron of the rhombicuboctahedron.The mineral displays a well-developed habit of deltoidal icositetrahedra with dull faces. — 1994 formsdeltoidal icositetrahedra · deltoidal icositetrahedrons