As nouns the difference between rhombohedron and octahedron
is that rhombohedron is a prism with six faces, each a rhombus while octahedron is a polyhedron with eight faces; the regular octahedron has regular triangles as faces and is one of the Platonic solids.
rhombohedron
English
Noun
(en-noun)
A prism with six faces, each a rhombus.
octahedron
English
Noun
(en-noun)
(geometry) a polyhedron with eight faces; the regular octahedron has regular triangles as faces and is one of the Platonic solids.