正せい二に十じゅう面めん体たいせいにじゅうめんたいじ字FuriganaMeanings1nounregular icosahedronmathematics›A polyhedron with twenty equilateral triangular faces, five meeting at each vertex; a Platonic solid.正せい二に十じゅう面めん体たいはプラトンの立りっ体たいの一ひとつ
