(1):

(a.) Not willing to speak; mute; silent; not speaking; not accompanied by words; as, dumb show.

(2):

(a.) Lacking brightness or clearness, as a color.

(3):

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

(4):

(v. t.) To put to silence.