When you smear feces on a surface that is not of your own property (If it's your own property... why the hell are you brown walling it?!) to getrevenge on someone.
Did you brown wall Meredith's place last night? Yeah, I did, I brown walled her whole place. That bitch got what she deserved for cheating on me. Have fun cleaning that up!
When one takes their gun (preferably a .45 magnum) and inserts it into their partners anus. The revolver is then removed from the partners caverns covered in shit, making it brown. It is common for at least one partner to experience death, as most people don't know how to properly set their safety