adjective, dumber, dumbest.
lacking intelligence or good judgment; stupid; dull-witted.
lacking the power of speech (offensive when applied to humans):
a dumb animal.
temporarily unable to speak:
dumb with astonishment.
refraining from any or much speech; silent.
made, done, etc., without speech.
lacking some usual property, characteristic, etc.
performed in pantomime; mimed.
Computers. pertaining to the inability to do processing locally:
A dumb terminal can input, output, and display data, but cannot process it.
Compare (def 4).
dumb down, Informal. to make or become less intellectual, simpler, or less sophisticated:
to dumb down a textbook; American movies have dumbed down.
lacking the power to speak, either because of defects in the vocal organs or because of hereditary deafness
lacking the power of human speech: dumb animals
temporarily lacking or bereft of the power to speak: struck dumb
refraining from speech; uncommunicative
producing no sound; silent: a dumb piano
made, done, or performed without speech
(of a projectile or bomb) not guided to its target
Old English dumb “silent, unable to speak,” from PIE *dheubh- “confusion, stupefaction, dizziness,” from root *dheu- (1) “dust, mist, vapor, smoke,” and related notions of “defective perception or wits.”
The Old English, Old Saxon (dumb), Gothic (dumbs), and Old Norse (dumbr) forms of the word meant only “mute, speechless;” in Old High German (thumb) it meant both this and “stupid,” and in Modern German this latter became the only sense. Meaning “foolish, ignorant” was occasionally in Middle English, but modern use (1823) comes from influence of German dumm. Related: dumber; dumbest.
Applied to silent contrivances, hence dumbwaiter. As a verb, in late Old English, “to become mute;” c.1600, “to make mute.” To dumb (something) down is from 1933.
Stupid; mentally sluggish; dim: You think I’m pretty dumb, don’t you? (1823+)
damn, darn (1787+)
[fr Pennsylvania German dumm]
from natural infirmity (Ex. 4:11); not knowing what to say (Prov. 31:8); unwillingness to speak (Ps. 39:9; Lev. 10:3). Christ repeatedly restored the dumb (Matt. 9:32, 33; Luke 11:14; Matt. 12:22) to the use of speech.
[duhm-found, duhm-found] /dʌmˈfaʊnd, ˈdʌmˌfaʊnd/ verb (used with object) 1. to make speechless with amazement; astonish. /dʌmˈfaʊnd/ verb 1. (transitive) to strike dumb with astonishment; amaze v. 1650s, from dumb (adj.) + ending from confound.
[duhm-found, duhm-found] /dʌmˈfaʊnd, ˈdʌmˌfaʊnd/ verb (used with object) 1. to make speechless with amazement; astonish. /dʌmˈfaʊnd/ verb 1. (transitive) to strike dumb with astonishment; amaze adj. past participle adjective from dumbfound. v. 1650s, from dumb (adj.) + ending from confound.
[duhm-hed] /ˈdʌmˌhɛd/ noun, Slang. 1. . noun Astupidperson: This dumbhead has just gone nuts/ the dumbfuck who thought that up [1887+; perhaps fr German Dummkopf]