We found 28 dictionaries that define the word tetrahedron:

General (22 matching dictionaries)

1. tetrahedron: Merriam-Webster
2. tetrahedron: Oxford Learner's Dictionaries
3. tetrahedron: American Heritage Dictionary of the English Language
4. tetrahedron: Collins English Dictionary
5. tetrahedron: Vocabulary.com
6. Tetrahedron, tetrahedron: Wordnik
7. tetrahedron: Cambridge Advanced Learner's Dictionary
8. tetrahedron: Wiktionary
9. tetrahedron: Webster's New World College Dictionary, 4th Ed.
10. tetrahedron: The Wordsmyth English Dictionary-Thesaurus
11. tetrahedron: Infoplease Dictionary
12. tetrahedron: Dictionary.com
13. tetrahedron: Online Etymology Dictionary
14. Tetrahedron (journal), Tetrahedron: Wikipedia, the Free Encyclopedia
15. Tetrahedron: Online Plain Text English Dictionary
16. tetrahedron: Webster's Revised Unabridged, 1913 Edition
17. tetrahedron: Rhymezone
18. Tetrahedron: AllWords.com Multi-Lingual Dictionary
19. tetrahedron: Webster's 1828 Dictionary
20. tetrahedron: FreeDictionary.org
21. tetrahedron: Mnemonic Dictionary
22. tetrahedron: TheFreeDictionary.com

Art (1 matching dictionary)

23. tetrahedron: ArtLex Lexicon of Visual Art Terminology

Computing (1 matching dictionary)

24. tetrahedron: Encyclopedia

Medicine (1 matching dictionary)

25. online medical dictionary (No longer online)

Science (3 matching dictionaries)

26. tetrahedron: LITTLE EXPLORERS(TM) Picture Dictionary
27. Tetrahedron: Eric Weisstein's World of Mathematics
28. tetrahedron, tetrahedron: PlanetMath Encyclopedia

(Note: See tetrahedra as well.)

Definitions from Wiktionary (tetrahedron) ▸ noun:  (geometry) A polyhedron with four faces; the regular tetrahedron, the faces of which are equal equilateral triangles, is one of the Platonic solids. Similar: tetraedron, tetraedrum, octaedron, hexoctahedron, hexatetrahedron, tetradecahedron, tetrahexahedron, tetrakaidekahedron, pentatope, icositetrahedron, more... Types: regular tetrahedron, prism, pyramid, truncated pyramid, more... Phrases: regular tetrahedron, truncated tetrahedron, Tetrahedron in Bottrop, more... Adjectives: regular, truncated, distorted, irregular, double, single, smaller, equilateral, central, original, dimensional Colors:     red,     blue,     green,     yellow,     orange, more... ▸ Word origin ▸ Words similar to tetrahedron ▸ Usage examples for tetrahedron ▸ Idioms related to tetrahedron ▸ Wikipedia articles (New!) ▸ Popular adjectives describing tetrahedron ▸ Words that often appear near tetrahedron ▸ Rhymes of tetrahedron ▸ Invented words related to tetrahedron