1. the quality or state of being stupid; lack of intelligence or common sense
2. a stupid act, remark, or idea

Examples

• His stupidity cost him the job opportunity.
• The plan failed due to sheer stupidity.
• She couldn’t believe the stupidity of his comment.
• The accident was caused by a moment of stupidity.
• Their stupidity in handling money led to bankruptcy.
• He regretted the stupidity of his decision.
• The movie was full of plot holes and stupidity.