The phenomenon when a girl with a bit of pudge on her stomach wears tight pants but a top that shows her midriff, causing her belly fat to spill over the edge of her pants. Much like the way that biscuit dough oozes out of the container. Also known as muffin belly. See biscuit hips.
She's got a bit of a biscuit belly, I'd hit it after 3 beers.