Keywords: stupid, stupidity, idiocy
As a Noun
1. Behaviour which is not at all sensible. English = stupidity.
2. The quality of being stupid. English = stupidity.
3. The quality of being very stupid. English = idiocy.
As a Verb or Adjective
1. To show a lack of good judgement or intelligence and to be not at all sensible. English = (be) stupid.