2 : in a state of mental numbness especially as resulting from shock; "he had a dazed expression on his face"; "lay semiconscious, stunned (or stupefied) by the blow"; "was stupid from fatigue"
3 : 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"
4 : so unreasonable as to invite derision; "the absurd excuse that the dog ate his homework"; "that's a cockeyed idea"; "ask a nonsensical question and get a nonsensical answer"; "a contribution so small as to be laughable"; "it is ludicrous to call a cottage a mansion"; "a preposterous attempt to turn back the pages of history"; "her conceited assumption of universal interest in her rather dull children was ridiculous"
5 : devoid of intelligence or thought; "a vacuous mind"; "a vacant expression"
adjectif
1 : lacking intelligence
2 : lacking or marked by lack of intellectual acuity
