inbetweener

in between +‎ -er

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.
   • 2011, Wayne Purdy, A Juniper Through The Cracks, page 86:

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

   • 2014, Elly Blue, Everyday Bicycling, page 47:

     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.

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

     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.