If you describe someone as impudent, you mean they are rude or disrespectful, or do something they have no right to do. [formal, disapproval]
Some of them were impudent and insulting.
Synonyms: bold, rude, cheeky [informal], forward
impudence uncountable noun One sister had the impudence to wear the other's clothes.
Synonyms: boldness, nerve [informal], cheek [informal], face [informal]