1. Abbr. TD Football An act of carrying, receiving, or gaining possession of the ball across the opponent's goal line for a score of six points.
2. The contact, or moment of contact, of a landing aircraft or spacecraft with the landing surface.
[From the earlier practice of touching the ball to the ground behind the goal line.]
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.