—adj. 1. lacking ordinary quickness and keenness of mind; dull.
2. characterized by or proceeding from mental dullness; foolish; senseless: a stupid question. 3. tediously dull, esp. due to lack of meaning or sense; inane; pointless: a stupid party. 4. annoying or irritating; troublesome: Turn off that stupid radio. 5. in a state of stupor; stupefied: stupid from fatigue. 6. Slang.excellent; terrific.