
English word dumb comes from Proto-Indo-European *dheubh-
*dheubh- (Proto-Indo-European)
*dumbōną (Proto-Germanic)
dumbian (Old English)
dumbien (Middle English)
dumb (English)
(dated) To silence.. (transitive) To make stupid.. (transitive) To reduce the intellectual demands of.. (transitive) To represent as stupid.