A vagina. Usually one that is quite moist, produces thick white matter and has quite a salty flavor.
By fucking Angie for almost three hours, Rob turned her once thin and delicate quim into a foaming seabiscuit.
(noun) The bubbling fuzz produced from rapid fucking. 2. A pussy that has an unusually large amount of discharge. 3. An infected vagina. 4. The froth on a horse's mouth.
A man says to his son, "When it comes to women; look before you leap. If you see a foaming seabiscuit, get the hell out of there!"