二十面體
Icosahedron \I`co*sa*he"dron\, n. [Gr. ?; ? twenty + ? seat,
base, fr. ? to sit.] (Geom.)
A solid bounded by twenty sides or faces.
{Regular icosahedron}, one of the five regular polyhedrons,
bounded by twenty equilateral triangules. Five triangles
meet to form each solid angle of the polyhedron.
icosahedron
n : any polyhedron having twenty plane faces
[also: {icosahedra} (pl)]