1. A connection or association: the tie-in between economic hardship and civil strife.
a. A media product, such as a book, video game, or movie, that makes use of material presented in another, usually more well-known media product: a video game that was a tie-in to a popular movie.
b. An advertisement or promotional action connecting one brand or product with another or with a popular event.
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.