1.
Overspill is used to refer to people who live near a city because there is no room in the city itself. (BRIT)
...new towns built to absorb ~ from nearby cities.
N-UNCOUNT: also a N, oft N n
2.
You can use ~ to refer to things or people which there is no room for in the usual place because it is full.
With the best seats taken, it was ruled that the ~ could stand at the back of the court.
N-UNCOUNT: also a N