- (mathematics) A four-dimensional object equivalent to a hexagon, constructed out of twenty-four octahedra.
2011, Jin Akiyama and Ikuro Sato, The element number of the convex regular polytopes, page 270:
- There are six convex regular 4-polytopes; five of these are the higher dimensional analogs of the Platonic solids, and one additional figure, the icositetrachoron, has no three-dimensional equivalent.
2012, Andrzej Katunin, Fractals based on regular convex polytopes, page 56:
- The icositetrachoron (hyperdiamond, octaplex or 24-cell) is the most unique polychoron, because it has no direct analog in any other dimension.
2012, Raymond Aschheim, Spin foam with topologically encoded tetrad on trivalent spin networks:
- Shape of Nature comes from a unique, optimally symmetric geometric object: the sixth platonic element, the icositetrachoron (or 24-cell regular polytope), crystallized as a hyperdiamond network, mathematically and physically made of loops and connections.