Any of various water-soluble protein derivatives formed by partial hydrolysis or digestion of proteins by an acid or enzyme, used in culture media in bacteriology.
[German Pepton, from Greek peptos, digested, from peptein, to digest; see pekw- in the Appendix of Indo-European roots.]
pep·tonic (-tŏnĭk) adj.
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.