Main Entry: tet·ra·he·dron

Pronunciation: \ˌte-trə-ˈhē-drən\

Function: noun

Inflected Form(s): plural tet·ra·he·drons or tet·ra·he·dra \-drə\

Etymology: New Latin, from Late Greek tetraedron, neuter of tetraedros having four faces, from Greek tetra- + hedra seat, face — more at sit

Date: 1570

: a polyhedron that has four faces

[tetrahedron illustration]