nonacoptic

English

The small stellated dodecahedron is a nonacoptic polyhedron.

Etymology

non- +‎ acoptic, introduced by the mathematician Branko Grünbaum to clarify terminology in the geometry of polygons and polyhedra. Initially he used the term coptic, but abandoned it in favor of nonacoptic in later writings.

Adjective

nonacoptic (not comparable)

1. (geometry, uncommon) Self-intersecting.
   • 1999, Grünbaum, Branko, "Acoptic polyhedra", Advances in discrete and computational geometry (South Hadley, MA, 1996) (PDF), Contemp. Math., 223, Amer. Math. Soc., Providence, RI, pp. 163–199, doi:10.1090/conm/223/03137, MR 1661382.

     See Norgate [N2], where nonacoptic pentahedra are investigated as well.

Antonyms

• acoptic