Kids In Parents' Pockets Eroding Retirement Savings
(a.k.a. boomerangers, nest-squatters)
It refers to British 20- and 30-something year olds who are still living at home. Also known as "boomerangers" in Canada and "nest-squatters" in Germany, it specifically
refers to people well into their 30's who have "failed to launch" and still live with their parents.