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.
In effect, Musk is leaving the mainstream car market to the Chinese—who, he has suggested, are so formidable that many Western automakers are unable to compete without government intervention.
From The Wall Street Journal ● Oct. 17, 2026
Any of those delays could have meant the police would have been unable to gather the evidence they wanted, they argued - and "given the gravity of this investigation", the police asked for search warrants.
From BBC ● Oct. 16, 2026
Pyongyang said its latest AI-assisted hypersonic missile followed a "wave-like trajectory" that left South Korea and Japan unable to track it effectively.
From Barron's ● Oct. 16, 2026
It allowed the team to examine how the hippocampus responds to sounds and language while patients are unconscious and unable to report what they experience.
From Science Daily ● Oct. 15, 2026
I press the letter into my lap, unable to contain the grin that’s taken over my face.
From "Red Flags and Butterflies" by Sheryl Azzam
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Get a wordDefinitions 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.
