In its original definition, it is a polyhedron with regular faces and a symmetry group which is transitive on its vertices, which is more commonly referred to today as a uniform polyhedron (this follows from Thorold Gosset's 1900 definition of the more general semiregular polytope).
Polyhedron | polyhedron | Polyhedron (magazine) | Kepler–Poinsot polyhedron | Kepler-Poinsot polyhedron |