An instance where someone has had botox on their forhead area but the muscles have contracted (then been frozen in place), forming a verticle frown line, much like a butt crack. Hence buttox.
A buttox is also a booty, a booty is also known as a pelvis, a pelvis is also known as a bum, a bum is also known as gluteus maximus and that is the thing you use to shake in peoples faces.
