1. Lacking physical strength or vigor; weak.
2. Lacking in power, as to act effectively; helpless: "Technology without morality is barbarous; morality without technology is impotent" (Freeman J. Dyson).
3. Incapable of sexual intercourse because of an inability to achieve or sustain an erection.
4. Obsolete Lacking self-restraint.
[Middle English, from Old French, from Latin impotēns, impotent- : in-, not; see IN-1 + potēns, potent; see POTENT.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.