jackernape
A dirty word you use when someone is acting like a total idiot and you're too mad to think straight.
My dad is a jackernape. He said I couldn't go to the concert because I didn't do my homework.
My sister is a jackernape. She took my phone and locked it and I had to beg her for it.
My cat is a jackernape. It knocked my food on the floor and then ate it.