A semi-regular polyhedron constructed from two congruent n-sided polygons and n parallelograms. The word comes from the Greek prizma, which relates to cutting or sawing. A prismoid resembles a prism but has bases that are similar rather than congruent, and sides that are trapezoids rather than parallelograms. An example of a prismoid is the frustum of a pyramid. A prismatoid is a polyhedron with all its vertices lying in two parallel planes.
