Definition:Octahedron

Definition
An octahedron is a polyhedron which has $8$ faces.

Linguistic Note
The word octahedron derives from the Classical Greek:
 * octo (ὀκτώ), meaning eight
 * hedron (a form of ἕδρα), meaning base or seat.

The technically correct plural of octahedron is octahedra, but the word octahedrons can often be found.