Origin: Greek suffix -hedron
Tetrahedron has 2 different meanings across 1 category:
any polyhedron having four plane faces
A polyhedron with four faces; the regular tetrahedron, the faces of which are equal equilateral triangles, is one of the Platonic solids.
The word comes from Ancient Greek, where it originally meant a pyramid with a triangular base. It is formed by combining elements meaning "four" and "seat."