• (n.) A twenty-four-sided solid; a tetragonal trisoctahedron or trapezohedron.
I`co·si·tet`ra·he'dron noun [ Greek ... twenty + ..., combining form of ... four + ... seat, base.] (Crystallog.) A twenty-four-sided solid; a tetragonal trisoctahedron or trapezohedron. 
An icositetrahedron is a twenty-four-sided solid shape.
a solid figure having 24 faces.