adjective

1. lacking the power of speech; mute: now regarded as offensive
2. unwilling to talk; silent
3. not accompanied by speech
4. temporarily speechless, as from fear
5. producing no sound
6. lacking some normal part, characteristic, or quality
7. ☆

   Etymology: Ger dumm

   Informal stupid; moronic
8. Comput. designating or of a terminal not equipped with its own processor
   cf. intelligent (sense )

Etymology: ME & OE, akin to Ger dumm (Goth dumbs), mute, stupid < nasalized var. of IE *dheubh < base *dheu-: see dull