[adjective] -er, -est - foolish or unwise; lacking judgment or intelligenceShe was really stupid to quit her job like that.Whose stupid idea was it to travel at night?One more stupid mistake like that and the whole deal could fall apart.You've said that retiring early was a stupid thing to do. Why did you do it?It would be stupid not to take the threats seriously.(informal) A person might also say a thing is stupid because it annoys them or has in some way caused them a problem.Have your stupid book back if it's so important to you.I hate doing this stupid exercise, I just can't get it right.
STUPID
Meaning of STUPID in English
Cambridge English vocab. Кембриджский английский словарь. 2012