Synonyms for dumb

modified

1. Unable to speak

   silent, mute, voiceless, speechless, inarticulate, wordless, quiet, mum, aphonic, deaf and dumb*; see also mute 1, quiet 2.

2. Temporarily speechless

   speechless, tongue-tied, dumbstruck, wordless, at a loss for words; see also surprised.

3. *Stupid

   simple-minded, feeble-minded, moronic; see dull 3, stupid 1.

dumb implies a lack of the power of speech and is now more often applied to brute animals and inanimate objects than to persons with impaired speech organs a dumb beast; voiceless is applied to one who has no voice, either from birth or through deprivation the throat operation left him voiceless; speechless usually implies temporary or momentary deprivation of the ability to speak speechless with horror; mute is applied to persons incapable of speech because of congenital deafness and not through absence or impairment of the speech organs