## tetrahedron

tet·ra·he·dron *pl.* -·drons or -·dra

a solid figure with four triangular faces

Origin of tetrahedron

Modern Latin ; from neuter of Late Greek*tetraedros,*four-sided: see tetra- and amp; -hedron

## tetrahedron

noun

*pl.*

**tet·ra·he·drons**or

**tet·ra·he·dra**

A polyhedron with four faces.

Origin of tetrahedron

Greek*tetraedron*, from neuter of

*tetraedros*,

*four-faced*:

*tetra-*,

*tetra-*+

*-hedros*,

*sided*; see

**–hedron**.

**tetrahedron**

## tetrahedron

Noun

(*plural* tetrahedrons *or* tetrahedra)

- (geometry) a polyhedron with four faces; the regular tetrahedron, the faces of which are equal equilateral triangles, is one of the Platonic solids.

Origin

From Ancient Greek *Ï„ÎµÏ„ÏÎ¬ÎµÎ´ÏÏŒÎ½* (tetraedron, “triangle-based pyramid"), from *Ï„ÎµÏ„ÏÎ¬ÎµÎ´ÏÏŒÏ‚*, from *Ï„ÎµÏ„ÏÎ¬Ï‚* (tetras, “four") + *á¼•Î´ÏÎ±* (hedra, “seat").