- (mathematics) A four-dimensional object analogous to a dodecahedron, constructed out of one hundred and twenty dodecahedra, arranged 4 to a vertex.
- 2011, Jin Akiyama and Ikuro Sato, The element number of the convex regular polytopes, page 271:
- The pentachoron, the hecatonicosachoron, and the hexacosichoron all have dichoral angles which are not divisors of 2π, and consequently, they are not space-filling.
- 2012, Andrzej Katunin, Fractals based on regular convex polytopes, page 57:
- The hecatonicosachoron (dodecaplex or 120-cell) and the hexacosichoron (tet- raplex or 600-cell) are also unique polychora, which have no analogs in higher dimensions.
- 2012, Richard Elwes, How to Solve the Da Vinci Code:
- The pentachoron, hypercube, orthoplex, hecatonicosachoron, and hexacosichoron are analogues of the ordinary Platonic solids.