Great Wall of China
A line of fortifications across northern China. Originally built during the Qin Dynasty (221-206 BC) by connecting earlier fortifications, it was subsequently rebuilt and altered many times. The wall reached its greatest extent during the improvements of the Ming Dynasty (1368-1644), when it was expanded to about 6,400 km (4,000 mi) long.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.