The longest river in the world, flowing about 6,675 km (4,150 mi) through eastern Africa from its most remote sources in Burundi to a delta on the Mediterranean Sea in northeast Egypt. The main headstreams, the Blue Nile and the White Nile, join at Khartoum in Sudan to form the Nile proper. The river has been used for irrigation in Egypt since at least 4000 BC, a function now regulated largely by the Aswan High Dam.
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.