Informal; used chiefly attributively.
Translations
That was a dimwit idea, destined to fail.
C'était une idée imbécile, vouée à l'échec.
stupideFamilier ; valeur plus neutre que « imbécile » dans certains contextes. Definitions
Informal, attributive: foolish or showing a lack of intelligence. That was a dimwit idea, destined to fail.