re·du·pli·cate (rĭ-dplə-kāt′, -dy-)
v. re·du·pli·cat·ed, re·du·pli·cat·ing, re·du·pli·cates
1. To repeat over and again; redouble.
a. To double (the initial syllable or all of a root word) to produce an inflectional or derivational form.
b. To form (a new word) by doubling all or part of a word.
To be doubled.
[Late Latin reduplicāre, reduplicāt- : Latin re-, re- + Latin duplicāre, to duplicate; see DUPLICATE.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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:
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.