—adj.
1 unintelligent, slow-witted, foolish (a stupid fellow).
2 typical of stupid persons (put it in a stupid place).
3 uninteresting or boring.
4 in a state of stupor or lethargy.
5 obtuse; lacking in sensibility.
—n. colloq. a stupid person.
Derivatives:
stupidity n. (pl. -ies). stupidly adv.
Etymology: F stupide or L stupidus (as STUPENDOUS)
Useful english dictionary. 2012.