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"学ぶ、あるいは理解するのが遅い魯鈍
例:dumb officials make some really dumb decisions 馬鹿な公務員はいくつかの本当に馬鹿な決定をする