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ad·den·dum

(ə-dĕndəm)

n. pl. ad·den·da (-də)

Something added or to be added, especially a supplement to a book.

[Latin, neuter gerundive of addere, to add; see ADD.]

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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