n. pl. pros·the·ses (-sēz)
1. An artificial device used to replace a missing body part, such as a limb, tooth, eye, or heart valve.
2. Replacement of a missing body part with such a device.
3. Linguistics Prothesis.
[Greek, addition, from prostithenai, prosthe-, to add : pros-, pros- + tithenai, to put; see dhē- in the Appendix of Indo-European roots.]
(click for a larger image)prosthesis
athlete wearing a prosthetic leg used for running
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.