[dumb] adj [ME, fr. OE; akin to OHG tumb mute] (bef. 12c) 1: lacking the power of speech "deaf and ~ from birth" "~ animals"
2: temporarily unable to speak (as from shock or astonishment) "struck ~ with fear"
3: not expressed in uttered words "~ grief"
4: silent; also: taciturn
5: lacking some usual attribute or accompaniment; esp: having no means of self-propulsion "~ barge"
6. a: markedly lacking in intelligence: stupid b: showing a lack of intelligence c: having little or no meaning--sometimes used in the phrase dumb luck 7: not having the capability to process data "a ~ terminal"--compare intelligent 3a syn see stupid -- dumb.ly adv -- dumb.ness n usage There is evidence that, when applied to persons who cannot speak, dumb has come to be considered offensive.
[2]dumb vt (1608): to make silent: deaden "would lie around, ~ed by the drugs --Norman Mailer"