pyonzyl
Believe it or not, this is not a prescription drug but the phonetic spelling of the ebonic version of "pencil."

Often heard in southern region of the United States where both pyonzyls and education are in short supply.  Pyonzyls in the deep south are rarely used for writing but more often found stuck in the ceiling of high school classrooms and in the side of the necks of homie's or bro's of those who say 'pyonzyl.'
Brother: "Hey mah, can I borra pyonzyl?"  

Kid: "whatcha need one for?"

Brother: "So I can poke a hole in dis lautha chair!"