pep (pĕp) Informal
Energy and high spirits; vim: "The duchess is full of pep, that particularly American word that expresses precisely her energy and gaiety" (Suzy Menkes).
tr.v. pepped, pep·ping, peps
To bring energy or liveliness to; invigorate: The good news pepped him up.
[Short for PEPPER.]
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.