lacking intelligence or good judgment; stupid; dull-witted.
lacking the power of speech (often 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.
pertaining to the inability to do processing locally:Cf. intelligent (def. 4). A dumb terminal can input, output, and display data, but cannot process it.
(of a barge) without means of propulsion.
(of any craft) without means of propulsion, steering, or signaling.