Noun
Johnson solid (plural Johnson solids)
(geometry) Any of a class of convex polyhedra that have regular faces but are not uniform (that is, not Platonic solids, Archimedean solids, prisms, or antiprisms).
An example of a Johnson solid is the square-based pyramid with equilateral sides ( J 1 ); it has 1 square face and 4 triangular faces. Source: Internet