PARALLELOPIP'ED, noun [parallel and Gr. on, and a plain.]

In geometry, a regular solid comprehended under six parallelograms, the opposite ones of which are similar, parallel and equal to each other, or it is a prism whose base is a parallelogram. It is always triple to a pyramid of the same base and highth. Or a parallelopiped is a solid figure bounded by six faces, parallel to each other two and two.