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dec·a·gon

(dĕkə-gŏn′)

A polygon with ten sides and ten angles.

[Medieval Latin decagōnum, from Greek dekagōnon, from neuter of dekagōnos, having ten angles : deka, ten; see dek in the Appendix of Indo-European roots + -gōnos, angled; see -GON.]

de·cago·nal (dĭ-kăgə-nəl) adj.

de·cago·nal·ly adv.

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decagon

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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