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.
Examples of dumb in a sentence. 1  I'm not dumb enough to believe that. 2  It was a dumb idea in the first place. 3  He just stood there with a dumb grin on his face.  This is one of the dumbest TV shows I've ever 1  seen. It was dumb luck that we found this place at 2  all. His success is just a matter of dumb 3  luck. He was born deaf and  dumb.