cre·a·tine (krēə-tēn′, -tĭn) also cre·a·tin (-tĭn)
A compound, C4H9N3O2, that is found in the muscle tissue of vertebrates mainly in the form of phosphocreatine and that is involved in storing and supplying energy for muscle contraction.
[French créatine : from Greek kreas, kreat-, flesh; see kreuə- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. 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.