noun, plural tet·ra·he·drons, tet·ra·he·dra [te-truh–hee-druh] /ˌtɛ trəˈhi drə/.
- Geometry. a solid contained by four plane faces; a triangular pyramid.
- any of various objects resembling a tetrahedron in the distribution of its faces or apexes.
noun plural -drons or -dra (-drə)
- a solid figure having four plane faces. A regular tetrahedron has faces that are equilateral trianglesSee also polyhedron
- any object shaped like a tetrahedron
n.solid figure contained by four triangular surfaces, 1560s, from Late Greek tetraedron, originally neuter of tetraedros (adj.) “four-sided,” from tetra- “four” + hedra “seat, base, chair, face of a geometric solid,” from PIE root *sed- (1) “to sit” (see sedentary). Plural tetrahedrons tetrahedra
- A polyhedron having four faces.