Definition of "icosahedral"

icosahedral

adjective
not comparable
1. Of, relating to, or having the shape of an icosahedron.
  Quotations
  Of the convex polyhedra with regular faces, the only ones that have tetrahedral, octahedral, or icosahedral symmetry are the Platonic and Archimedean solids.
  1966, Norman W. Johnson, “Convex Polyhedra with Regular Faces”, in Canadian Journal of Mathematics, volume XVIII, number I, Toronto: University of Toronto Press, page 181