Of or relating to the cultural period of the Stone Age beginning with the earliest chipped stone tools, about 2.4 million years ago, until the beginning of the Mesolithic Period, about 15,000 to 11,500 years ago in western Asia and southern Europe.
The Paleolithic Period. Also called Old Stone Age. See Usage Note at Three Age system.
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.