• synonyms


[te-truh-hee-druh n]
noun, plural tet·ra·he·drons, tet·ra·he·dra [te-truh-hee-druh] /ˌtɛ trəˈhi drə/.
  1. Geometry. a solid contained by four plane faces; a triangular pyramid.
  2. any of various objects resembling a tetrahedron in the distribution of its faces or apexes.
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Origin of tetrahedron

1560–70; tetra- + -hedron, modeled on Late Greek tetráedron, noun use of neuter of tetráedros four-sided
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for tetrahedron

Historical Examples of tetrahedron

  • A scalene triangle abc might also be employed, or a tetrahedron.

    Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 2


  • The Tetrahedron, having four equilateral triangles as faces.

    Bygone Beliefs

    H. Stanley Redgrove

  • Its head was a pyramid, a tetrahedron; its length vanished in the further darkness.

  • It occurs crystallized in the form of the tetrahedron, also massive and disseminated.

  • Round Mars describe a tetrahedron; the sphere including this will be Jupiter.


    Walter W. Bryant

British Dictionary definitions for tetrahedron


noun plural -drons or -dra (-drə)
  1. a solid figure having four plane faces. A regular tetrahedron has faces that are equilateral trianglesSee also polyhedron
  2. any object shaped like a tetrahedron
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Derived Formstetrahedral, adjectivetetrahedrally, adverb

Word Origin for tetrahedron

C16: from New Latin, from Late Greek tetraedron; see tetra-, -hedron
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for tetrahedron


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).

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Online Etymology Dictionary, © 2010 Douglas Harper

tetrahedron in Science


Plural tetrahedrons tetrahedra
  1. A polyhedron having four faces.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.