1. The substructure or foundation of a building.
2. The lowest habitable story of a building, usually below ground level.
3. A complex of undifferentiated igneous and metamorphic rocks underlying sedimentary strata.
4. Slang The last place or lowest level, as in competitive standings.
5. Chiefly New England A public toilet, especially one in a school.
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.