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.
With the fire not yet extinguished, rescuers have been unable to search the vessel, Cayabyab said, adding that some people may still be trapped inside.
From Barron's ● Sep. 10, 2026
Agents believed there were some 374 other victims but were unable to either identify or contact them, lawyers for the government later said.
From The Wall Street Journal ● Sep. 10, 2026
Lantz confirmed all five people involved in the crash were adults but was unable to share further identifying information.
From Los Angeles Times ● Sep. 9, 2026
She questioned whether Burnham was "unable" or "just unwilling" to meet the 2030 target.
From BBC ● Sep. 9, 2026
I imagined Ma at fifteen or sixteen years old, unable to read or write, searching for a matchmaker.
From "The Red Car to Hollywood" by Jennie Liu
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.
