rhombicosidodecahedron

Learned borrowing from New Latin rhombicosidodecaēdron (coined by the German astronomer and mathematician Johannes Kepler (1571–1630) in his work Harmonices Mundi Libri V (The Harmony of the World in Five Books, 1619)), a blend of Latin rhomb(us) + īcos(aedron) + -i- + dodecaēdron. The English word is analysable as a blend of rhomb(ic) +‎ icosidodecahedron, referring to the fact that the 30 square faces lie in the same planes as the 30 rhombic faces of the rhombic triacontahedron, which is dual to the icosidodecahedron.