The addition of -ity to an adjective results in a shift of stress to the antepenultimate syllable; that is, words in -ity are stressed on the last syllable before the -ity, even in cases where this syllable is part of another suffix (as in words in -ability and -icity).
adjective, dumber, dumbest. 1. lacking intelligence or good judgment; stupid; dull-witted. 2. lacking the power of speech (offensive when applied to humans): a dumb animal.
(=unable to speak) muet (te) She's deaf and dumb. Elle est sourde-muette. â a young deaf and dumb man. to be struck dumb (fig) rester abasourdi (e) , Ãªtre sidÃ©rÃ© (e) â We were all struck dumb for a minute. (=stupid) [person] bÃªte. â I've met a lot of really dumb people.