Question

what is definition of stupid

Answer 1

not intelligent or sensible.
or
silly or unwise; showing poor judgment or little intelligence.

I hope this will help you

Answer 2

If you say that someone or something is stupid, you mean that they show a lack of good judgment or intelligence and they are not at all sensible.

I'll never do anything so stupid again

A stupid person doesn't have much intelligence or imagination, and they go through life making decisions that seem to lack all common sense.