The gluteus maximus is the main extensor muscle of the hip. It is the largest and outermost of the three gluteal muscles and makes up a large part of the shape and appearance of each side of the hips.
Referring to the maximum amount of area a butt can take up. When the person gets more whalelike the amount of area it takes up increases. Quite often when sitting down the butt takes on the characteristics of a couch.
That gluteus maximus doesn't fit through the door. Son that's not what your looking for. Look how much area it takes up.