Acronym for Kids In Parents' Pockets Eroding Retirement Savings.
Used to describe young(ish) people who should have moved out of the parental home but have refused to give up the easy lifestyle and perks that this entails. As a result this costs the parents in money and time.
Dude, you're 27, do you still live with your Mom?
Yeah, so does my bro. We got it sweet, we're kippers!