Loss of memory, usually resulting from shock, psychological disturbance, brain injury, or illness.
[Greek amnēsiā, forgetfulness, probably alteration of amnēstiā, from amnēstos, not remembered : a-, not; see A–1 + mimnēskein, mnē-, to remember; see men-1 in the Appendix of Indo-European roots.]
am·nesi·ac′ (-nēzē-ăk′, -zhē-ăk′), am·nesic (-zĭk, -sĭk) n.& adj.
am·nestic (-nĕstĭk) adj.
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.