unable
Americanadjective
adjective
-
lacking the necessary power, ability, or authority (to do something); not able
-
archaic incompetent
Synonym Usage
See incapable.
Etymology
Origin of unable
Explanation
If you're unable to do something, you just can't do it. This isn't necessarily a bad thing! You may be unable to tell a lie, no matter how much you want to blame your brother for breaking that window. When we're unable, we're incapable. If you're unable to speak French, but you speak German fluently, you might choose to spend the summer in Berlin rather than Quebec City. And when your neighbor is unable to walk her dog during the day, you could volunteer to walk it after school. Being unable is either "lacking ability," or "lacking power."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Being a household name is no guarantee of a trademark, however: LeBron James found this out when he was unable to trademark “Taco Tuesday.”
From Salon • Jul. 7, 2026
Even Le Pen herself had designated her 30-year-old protégé, Jordan Bardella, as her party’s presidential candidate if she were unable to run.
From The Wall Street Journal • Jul. 7, 2026
Last year, Harry said he felt unable to bring his family to Britain after losing a court case to have his security restored during visits home.
From Barron's • Jul. 7, 2026
These allow someone else to act on your behalf to make financial and medical decisions should you become unable to do so.
From MarketWatch • Jul. 6, 2026
“You’ve been unable to move on to the Afterlife for a reason. A very specific reason. In fact, it is the same reason I was kept here six years ago.”
From "The Undead Fox of Deadwood Forest" by Aubrey Hartman
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
