Dumb

(a.) Destitute of the power of speech; unable; to utter articulate sounds; as, the dumb brutes.

Dumb - Other Definitions

(a.) Destitute of the power of speech; unable; to utter articulate sounds; as, the dumb brutes.
(a.) Not willing to speak; mute; silent; not speaking; not accompanied by words; as, dumb show.
(a.) Lacking brightness or clearness, as a color.
(v. t.) To put to silence.
(adv.) In silence; mutely.