a. Lacking the necessary ability, capacity, or power: incapable of carrying a tune; incapable of love.
b. Unable to perform adequately; incompetent: an incapable administrator.
2. Not susceptible to action or treatment: a unique feat, incapable of duplication.
a. Not meeting the physical and mental requirements imposed by law for the performance of a particular task.
b. Not meeting the requirements necessary for proper legal functioning: a contract provision incapable of being enforced.
in·ca′pa·bili·ty, in·capa·ble·ness n.
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.