Of a person: lacking the power of speech; unable to speak owing to a congenital or pathological condition; dumb. (In quot. 1400 functioning as a…

Of a person: keeping or maintaining silence; refraining from or tending to refrain from speech or utterance; unable to speak.

Having no voice; lacking the power or impulse to make vocal sounds; uttering no words or speech; dumb, mute.

Unmusical, unharmonious; voiceless.

(un-, prefix1 affix 1.)