Etymology

From . Cognate with the . In ordinary spoken English, a phrase like "He is dumb" is interpreted as "He is stupid" rather than "He lacks the power of speech". The latter example, however, is the original sense of the word. The senses of stupid, unintellectual, and pointless were established from influence of the word dumm.

Adjective

1. Unable to speak; lacking power of speech.

   His younger brother was born dumb, and communicated with sign language.

2. Of or pertaining to something, especially a person, that is extremely stupid.

   You dumb oaf, you can't fix an engine by hitting it with a hammer!

3. Pointless, foolish, lacking intellectual content or value.

   This is dumb! We're driving in circles! We should have asked for directions an hour ago!

   Brendan had the dumb job of moving boxes from one conveyor belt to another.

Synonyms

dumbstruck, mute, speechless, wordless feeble-minded, idiotic, moronic, stupid banal, brainless, dopey, silly, stupid, ridiculous, vulgar

Verb

1. To silence.
   • 1911, Lindsay Swift, William Lloyd Garrison, p. 272,

     The paralysis of the Northern conscience, the dumbing of the Northern voice, were coming to an end.

2. To make stupid.
   • 2003, Angela Calabrese Barton, Teaching Science for Social Justice, p. 124,

     I think she's dumbing us down, so we won't be smarter than her.

3. To represent as stupid.
   • 2004, Stephen Oppenheimer, The Real Eve: Modern Man's Journey Out of Africa, p. 107,

     Bad-mouthing Neanderthals . . . is symptomatic of a need to exclude and even demonize. . . . I suggest that the unproven dumbing of the Neanderthals is an example of the same cultural preconception.

4. To reduce the intellectual demands of.
   • 2002, Deborah Meier, In Schools We Trust: Creating Communities of Learning in an Era of Testing, p. 126,

     The ensuing storm caused the department to lower the bar—amid protests that this was dumbing the test down—so that only 80 percent of urban kids would fail.