An overspill of milk.
New towns were to accommodate overspill from established cities.
Coventry would also benefit from the overspill of freight traffic from the South East.
Because they sit on the hips, there's no unsightly overspill, either.
Underwire Camisoles: An underwire camisole provides the support of an underwire bra, but it shapes you down below to disguise the dreaded "back fat overspill."
If it doesn't, you will find that either your breasts are left unsupported, or that you are unable to move comfortably without feeling like there is some "overspill" to your garment.