Floater

Social floaters are middle school age, high school age, college age people, and even sometimes full adults who don't fully belong in a set group. They come in many types and can be rather diverse. They tend to drift between individual groups in search of a place to belong or happily befriend people from all kinds of groups. They can be popular or rather hidden, the defining trait is that they don't stick around with just one group or seem to exist devoid of a group. There's no universal trait to floaters other than the lack of a solid inter-connected friend group. Some may have severe anxiety and that may be the cause of their situation or others may be perfectly content and marching to the beat of their own drum.