(geometry) A polyhedron with twenty faces. / (geometry, specifically) A regular icosahedron: one of the Platonic solids, all of whose faces are regular (equilateral) triangles

plural of icosahedron

(geometry) A polyhedron that has thirty-two faces (12 regular pentagons and 20 regular hexagons) and 60 vertices and 90 edges, and is one of the Archimedean solids.

plural of truncated icosahedron

A polyhedron containing 10 triangular faces, 15 edges, and 6 vertices.

(geometry) One of four Kepler-Poinsot polyhedra with Schläfli symbol {3,5⁄2}.

plural of great icosahedron