unable

American  

[uhn-ey-buhl] / ʌnˈeɪ bəl /

adjective

1. lacking the necessary power, competence, etc., to accomplish some specified act.

   He was unable to swim.

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unable British  

/ ʌnˈeɪbəl /

adjective

1. lacking the necessary power, ability, or authority (to do something); not able

2. archaic incompetent

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Related Words

See incapable.

Etymology

Origin of unable

First recorded in 1350–1400; Middle English; un- ¹ + able

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

Some of the decline is simply the result of people exhausting their benefits after being unable to find a job.

From MarketWatch • May 7, 2026

Eight players who have made All-Star teams as recently as 2024—whose teams shell out combined salaries this season totaling $313.7 million—have been unable to report for playoff duty on at least one occasion.

From The Wall Street Journal • May 7, 2026

In Stumo's case, however, her family was unable to reach an agreement with Boeing ahead of the trial, which began on Monday with two days of jury selection.

From Barron's • May 6, 2026

Videos online show the British star being booed after suggesting she was unable to perform her song Illygal, about an undocumented migrant, because it could apply to members of the crowd.

From BBC • May 5, 2026

I leaned back in my chair, unable to stop my grin.

From "Bye Forever, I Guess" by Jodi Meadows

Related Words

• helpless
• impotent
• inadequate
• incapable
• not able
• powerless
• sidelined
• unfit
• weak