The pudge of flabby skin that hangs over the front of your pants at the waistline. It looks just like a muffin and how it rises out over the paper cup you bake them in.
I can't wear this half-top until I loose this muffin.
Used to describe the unattractive effect achieved when a girl wears pants that are too low cut and too tight. This creates a bulge of fat around the hip and stomach area, resembling the top of a muffin that is too big for its case.