From natural infirmity (Exodus 4:11); not knowing what to say (Proverbs 31:8); unwillingness to speak (Psalm 39:9; Leviticus 10:3). Christ repeatedly restored the dumb (Matthew 9:32, 33; Luke 11:14; Matthew 12:22) to the use of speech.

Noah Webster's New International Dictionary of the English Language

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

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

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

4. (v. t.) To put to silence.