du·plic·i·ty (d-plĭsĭ-tē, dy-)
n. pl. du·plic·i·ties
a. Deliberate deceptiveness in behavior or speech.
b. An instance of deliberate deceptiveness; double-dealing.
2. The quality or state of being twofold or double.
[Middle English duplicite, from Old French, from Late Latin duplicitās, doubleness, from Latin duplex, duplic-, twofold; see dwo- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.