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tet·ra·he·dron

(tĕt′rə-hēdrən)

n. pl. tet·ra·he·drons or tet·ra·he·dra (-drə)

A polyhedron with four faces.

[Greek tetraedron, from neuter of tetraedros, four-faced : tetra-, tetra- + -hedros, sided; see -HEDRON.]

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tetrahedron

Indo-European & Semitic Roots Appendices

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

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