1. adjective (used as a modifier before a noun) Being between two positions, conditions, situations, etc. During the interval of the play, the theater put on a small in-between performance. After college, many people struggle with the awkward in-between status of no longer being a student but not yet being a fully realized adult.

2. noun A person or thing who holds an intermediate position between two opposites or extremes. Personally, I feel like all the in-betweens who wouldn't vote one way or another were simply being weak-willed. I don't agree fully with the Democrats or the Republicans, so I guess I'm just an in-between.