wash·er (wŏshər, wôshər)
1. One who washes: a washer of clothes; a washer of windows.
2. An appliance, especially a washing machine, used for washing.
3. A flat disk, as of metal, plastic, rubber, or leather, placed beneath a nut or bolt to make the connection more secure or distribute pressure or placed between parts to space the parts properly or prevent leakage in a joint.
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.