inbetweener

plural inbetweeners

1. A person who specializes in tweening in an animation studio.
2. A person who or thing that falls between different groups or characteristics.

   More than an outsider he was an in-betweener; caught between two cultures all the while shunning his own.

   2011, Wayne Purdy, A Juniper Through The Cracks, page 86

   2 more examples

   But having two bikes works well for me—so well that I'm daydreaming about getting a third, an in-betweener, light and strong enough to carry me over mountains with a sleeping bag and tent on the back.

   2014, Elly Blue, Everyday Bicycling, page 47

   Now, Barney was what some voices referred to as an “inbetweener.” It met that he was never located in a permanent grade level. Back in those days when a student was found unfit of advancing to a higher level, he was held back for only half of the year and then advanced for the other half.

   2016, George Boldt, Once a Man—Twice a Boy