Destitute of the power of speech; unable; to utter articulate sounds; as, the dumb brutes.
Not willing to speak; mute; silent; not speaking; not accompanied by words; as, dumb show.
ADJECTIVE: In its past usage, dumb was a synonym for mute, or unable to speak. In its early nineteenth-century usage, it did not automatically reflect anything about mental or intellectual abilities. An example of its continuing use is the expression "dumb struck." It is now considered offensive.
unable to speak temporarily; "struck dumb"; "speechless with shock"
unable to speak because of hereditary deafness