- (mathematics) A four-dimensional object equivalent to an octahedron, constructed out of sixteen tetrahedra.
- 2005, V H Satheesh Kumar and P K Suresh, Are We Living in a Higher Dimensional Universe?, page 3:
- In a world with four spatial dimensions, for example, we can construct only six regular solids, viz pentatope, tesseract, hexadecachoron, icositetrachoron, hecatonicosachoron and hexacosichoron.
- 2009, P. Khavari and C. C. Dyer, Aspects of Causality in Parallelisable Implicit Evolution Scheme, page 7:
- We have chosen the surfaces of a pentatope (5-cell) as well as a hexadecachoron (16-cell), which are simple standard triangulations of a 3-sphere, shown in figure (7), as our underlying lattices.
- 2011, Jin Akiyama and Ikuro Sato, The element number of the convex regular polytopes, page 271:
- In four dimensions, surprisingly, there are three space-filling convex regular polychora: the tesseract (the hypercube in ℝ4), the hexadecachoron, and the icositetrachoron.