enneadecahedron

plural enneadecahedra · plural enneadecahedrons

1. raregeometryA polyhedron with nineteen faces.

   Guy [24] and Knowlton have independently discovered a uniform unistable enneadecahedron.

   1970, Research Paper, page 22

   2 more examples

   Klamkin noted that [1] contains an improved solution by R.K. Guy to the polyhedron problem, consisting of a doubly truncated 17-sided convex prism, making it an enneadecahedron (19 faces). […] Ogilvy referred to his book [4], where he describes Guy's enneadecahedron.

   1980, Crux Mathematicorum, pages 28, 29

   Our solid is a 17-sided prism, half of whose section is illustrated in Fig. 5, truncated obliquely as in the side view of Fig. 6, so it is an enneadecahedron.

   1990, Murray S. Klamkin, Problems in Applied Mathematics: Selections from SIAM Review, Society for Industrial and Applied Mathematics, →ISBN, page 478