dumb (
http://definr.com/dumb)
adj 1: slow to learn or understand; lacking intellectual acuity;
"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" [syn:
dense,
dim,
dull,
obtuse,
slow]
2: unable to speak temporarily; "struck dumb"; "speechless with
shock" [syn:
speechless]
3: lacking the power of human speech; "dumb animals"
4: unable to speak because of hereditary deafness [syn:
mute,
silent]