A term invented by B. Grünbaum in an attempt to promote concrete and precise Polyhedron terminology. The word ``coptic'' derives from the Greek for ``to cut,'' and acoptic polyhedra are defined as Polyhedra for which the Faces do not intersect (cut) themselves, making them 2-Manifolds.
See also Honeycomb, Nolid, Polyhedron, Sponge