Main entry: mute, dumb, silent
Definition: unable to speak because of hereditary deafness
Main entry: dumb
Definition: lacking the power of human speech
Usage: dumb animals
Main entry: dumb, speechless
Definition: temporarily incapable of speaking
Usage: struck dumb; speechless with shock
Main entry: dim, dense, dull, dumb, obtuse, slow
Definition: slow to learn or understand; lacking intellectual acuity
Usage: so dense he never understands anything I say to him; never met anyone quite so dim; although dull at classical learning, at mathematics he was uncommonly quick- Thackeray; dumb officials make some really dumb decisions; he was either normally stupid or being deliberately obtuse; worked with the slow students