dumb
Americanadjective
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lacking intelligence or good judgment; stupid; dull-witted.
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lacking the power of speech (offensive when applied to humans).
a dumb animal.
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temporarily unable to speak.
dumb with astonishment.
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refraining from any or much speech; silent.
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made, done, etc., without speech.
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lacking some usual property, characteristic, etc.
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performed in pantomime; mimed.
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Computers. pertaining to the inability to do processing locally.
A dumb terminal can input, output, and display data, but cannot process it.
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Nautical.
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(of a barge) without means of propulsion.
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(of any craft) without means of propulsion, steering, or signaling.
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verb phrase
adjective
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lacking the power to speak, either because of defects in the vocal organs or because of hereditary deafness
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lacking the power of human speech
dumb animals
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temporarily lacking or bereft of the power to speak
struck dumb
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refraining from speech; uncommunicative
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producing no sound; silent
a dumb piano
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made, done, or performed without speech
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informal
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slow to understand; dim-witted
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foolish; stupid See also dumb down
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(of a projectile or bomb) not guided to its target
Sensitive Note
Dumb in the sense “lacking the power of speech” is perceived as insulting when describing humans (but not animals), probably because dumb also means “stupid; dull-witted.” The noun dummy in the sense “person who lacks the power of speech” is also perceived as insulting, as are the terms deaf-and-dumb, deaf-mute, and mute. The adjective hard of hearing is acceptable though not the term of choice, partly because it lacks directness. The preferred term is deaf, which makes no reference to an inability to speak or communicate; the capitalized word Deaf signals membership in this community.
Other Word Forms
Derived Forms
Inflected Forms
Adjectives
Etymology
Origin of dumb
First recorded before 1000; Old English; cognate with Old Norse dumbr, Gothic dumbs, Old Saxon dumb, Old High German tump, German dumm
Explanation
Today, most of the time someone or something is described as dumb when it shows a lack of thought, like your dumb idea of wearing flip-flops in a snowstorm. Dumb is the Old English word that means "mute, speechless," and itself came from an even older word dheubh meaning "confusion, stupefaction, dizziness." Today, dumb still means "unable to speak," but it doesn't have anything to do with intelligence. Its other meaning, however, does. If you make a dumb mistake, it's something you could have avoided if you thought it through first.
Vocabulary lists containing dumb
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.
See Examples For:
It’s the making of a perfect joke: totally superfluous and uniquely dumb.
From Salon ● Jul. 12, 2026
At one school in Hampshire, "brick" or "dumb" phones are the only devices allowed, which can only be used to call or text and have very limited internet access.
From BBC ● Jun. 27, 2026
The latest “Scary Movie,” which simply recycles the title “Scary Movie,” is as lazy, dumb and offensive as the others.
From Los Angeles Times ● Jun. 5, 2026
Markwayne Mullin has a brilliantly dumb idea he’s workshopping.
From Slate ● May 30, 2026
“But maybe the best part,” I said, “is thinking how you could turn that really small dumb power into something completely awesome.”
From "Firegirl" by Tony Abbott
“We’re getting fatter and dumber, and our mental health is deteriorating,” the author writes, which is what “a half century-plus of mass-affluence consumerism has brought us.”
From The Wall Street Journal ● Jun. 2, 2026
"Rather than becoming dumber, we are becoming more specialised for the job," said Tania Esparza.
From BBC ● Mar. 4, 2026
More than anything else, it offers further evidence that Musk is a lot dumber than he ought to be, given his immense worldly success.
From Salon ● Nov. 2, 2025
“The future is a lot dumber than I thought it would be,” the worker said.
From Los Angeles Times ● Jul. 24, 2025
Pa got his “you’re dumber than dirt” expression.
From "Worth" by A. LaFaye
Collectively, they stand as a blunt reminder that war, the dumbest and most vicious human invention, occurs in time and space.
From Salon ● Jul. 4, 2026
The dumbest phrase in military history is Adolf Hitler saying “Let’s attack Russia in the winter.”
From Slate ● Jun. 24, 2026
NBA legend Charles Barkley branded the San Antonio Spurs "the dumbest basketball team in the history of civilisation" after the New York Knicks pulled off the biggest comeback in NBA Finals history.
From BBC ● Jun. 11, 2026
Among the dumbest birds are insectivores, such as bee-eaters, and giants, such as ostriches.
From The Wall Street Journal ● May 22, 2026
There it was, the world’s dumbest bird, dipping its dumb head down so its orange button eye could stare back at him.
From "Wringer" by Jerry Spinelli
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.