1. An underwater current flowing strongly away from shore, usually caused by the seaward return of water from waves that have broken against the shore.
2. A tendency, especially in thought or feeling, contrary to what seems the strongest: "As she talks nostalgically of her days of glory ... a poignant undertow emerges" (Tina Brown).
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.