Meaning of “stupid” - Learner’s Dictionary

stupid

adjective uk us /ˈstjuːpɪd/
SILLY

B1 silly or not intelligent:

That was a really stupid thing to do.
How could you be so stupid?
ANNOYING [ always before noun ] informal

used to show that you are annoyed about something which is causing a problem:

I can never get this stupid machine to work!
stupidity uk us /stjuːˈpɪdəti/ noun [ U ]
stupidly adverb

(Definition of “stupid” from the Cambridge Learner’s Dictionary © Cambridge University Press)