dumb

American  

[duhm] / dʌm /

adjective

dumber, comparative dumbest superlative

1. lacking intelligence or good judgment; stupid; dull-witted.

2. lacking the power of speech (offensive when applied to humans).

   a dumb animal.

3. temporarily unable to speak.

   dumb with astonishment.

4. refraining from any or much speech; silent.

5. made, done, etc., without speech.

6. lacking some usual property, characteristic, etc.

7. performed in pantomime; mimed.

8. Computers. pertaining to the inability to do processing locally.

   A dumb terminal can input, output, and display data, but cannot process it.

9. Nautical.

   1. (of a barge) without means of propulsion.

   2. (of any craft) without means of propulsion, steering, or signaling.

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verb phrase

1. dumb down to make or become less intellectual, simpler, or less sophisticated.

   to dumb down a textbook; American movies have dumbed down.

dumb British  

/ dʌm /

adjective

1. lacking the power to speak, either because of defects in the vocal organs or because of hereditary deafness

2. lacking the power of human speech

   dumb animals

3. temporarily lacking or bereft of the power to speak

   struck dumb

4. refraining from speech; uncommunicative

5. producing no sound; silent

   a dumb piano

6. made, done, or performed without speech

7. informal

   1. slow to understand; dim-witted

   2. foolish; stupid See also dumb down

8. (of a projectile or bomb) not guided to its target

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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

• dumbness
  noun
• quasi-dumb
  adjective
• dumbly
  adverb
• quasi-dumbly
  adverb

Inflected Forms

Adjectives

• dumber
  comparative
• dumbest
  superlative

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.

Example Sentences

Competing as “A Dumb Reporter” with a fictional $1 million, I challenged Grok and felt pretty smug early on.

From The Wall Street Journal • Jun. 18, 2026

We’re in one of the more unwelcome additions to a storied cinematic masterpiece: Dumb and Dumber To.

From Slate • May 23, 2025

When thinking about Scotland's prospects of turning the awe-inspiring, championship-chasing Les Bleus to a sickly shade of green on Saturday night in Paris, a scene from Dumb and Dumber comes to mind.

From BBC • Mar. 15, 2025

Matt K. Lewis is the author of “Filthy Rich Politicians” and “Too Dumb to Fail.”

From Los Angeles Times • Mar. 3, 2025

This was before Leah and I were gifted; I was still Dumb Adah.

From "The Poisonwood Bible" by Barbara Kingsolver

Related Words

• dull
• foolish