1. Wedged together at the broken ends. Used of a fractured bone.
2. Placed in the alveolus in a manner prohibiting eruption into a normal position. Used of a tooth.
3. Wedged or packed in, so as to fill or block an organ or a passage: impacted feces.
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.