EXAMPLES | WORD ORIGIN noun, plural tet·ra·he·drons, tet·ra·he·dra . [te-tr uh- hee-dr uh] /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. Origin of tetrahedron 1560–70; tetra-
, modeled on
Late Greek tetráedron,
noun use of neuter of
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for tetrahedra Historical Examples of tetrahedra
The globe, e, is a new form, the four
tetrahedra of the proto level making a single twelve-atomed one on the meta.
The atoms are arranged in two
tetrahedra with a common apex, and the relationship is maintained in the meta-body, a septet.
The smallest particles of fire are
tetrahedra, of air octahedra, of water icosahedra. British Dictionary definitions for tetrahedra noun plural -drons or -dra ( -drə) a solid figure having four plane faces. A regular tetrahedron has faces that are equilateral triangles See also polyhedron any object shaped like a tetrahedron Derived Forms tetrahedral, adjective tetrahedrally, adverb Word Origin for tetrahedron
C16: from New Latin, from Late Greek
tetraedron; see tetra-, -hedron
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
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Word Origin and History for tetrahedra 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).
Online Etymology Dictionary, © 2010 Douglas Harper
Plural tetrahedrons tetrahedra A polyhedron having four faces.
The American Heritage® Science Dictionary
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