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.
dumb bomb - a bomb that falls because of gravity and is not guided to a target. gravity bomb. bomb - an explosive device fused to explode under specific conditions. smart bomb - a bomb that can be guided (by a laser beam or radio) to its target; smart bombs have revolutionized aerial bombardment.