Boomerang Generation is a term that is applied to Western culture young adults graduating high school and college in the 21st century in Western culture. They are so named for the percentage of whom choose to share a home with their parents after previously living on their own—thus boomeranging back to their parents' residence.
The term can also be used to indicate only those members of this age-set that actually do return back home and not the whole generation. In as much as home-leaving practices differ by economic class, the term is most meaningfully applied to members of the middle class.
This idea was the premise of the film Failure to Launch (2006) about a thirty something slacker who suspects his parents of setting him up with his dream girl so he'll finally vacate their home. The film stars Matthew McConaughey, Sarah Jessica Parker, and Zooey Deschanel.