Regular solid with eight faces, each of which is an equilateral triangle. It is one of the five regular polyhedra or Platonic solids. The figure made by joining the midpoints of the faces is a perfect cube and the vertices of the octahedron are themselves the midpoints of the faces of a surrounding cube. For this reason, the cube and the octahedron are called dual solids.
/oktəheedrən/ noun ( pl octahedrons octahedra /-drə/ ) a polyhedron with eight faces octahedral adj . ...
pronunciation (1570) : a solid bounded by eight plane faces
In Euclidean geometry, a three-dimensional object composed of a finite number of polygonal surfaces (faces). Technically, a polyhedron is the bound