insolent
/ɪnˈsɒlənt/Definitions
1. adjective
having or showing a lack of respect for authority or tradition; impudently bold or impertinent
“He was fired for being insolent to his superior in front of the entire office.”
2. noun
a person who shows insolence; a person who acts with impudence
“The insolent youth refused to apologize for his actions.”