(geometry) A solid figure with many flat faces and straight edges. / (optics) A polyscope, or multiplying glass.

plural of polyhedron

(mathematics) Either of a pair of polyhedra in which the faces of one are equivalent to the vertices of the other.

(geometry) A polyhedron that is partially nonconvex.

(geometry) The simplest non-convex polyhedron that cannot be triangulated into tetrahedra without adding new vertices.

(mathematics) A mathematical formula relating the vertices, edges and faces of a polyhedron: V-E+F=2

(geometry) Synonym of Kepler solid