in between

• inbetween
• in-between

From in +‎ between, perhaps in imitation of similar phrases as in the middle of, in the midst of, etc.

• Rhymes: -iːn

in between (not comparable)

1. Between them.
   • 2013 June 7, David Simpson, “Fantasy of navigation”, in The Guardian Weekly, volume 188, number 26, page 36:

     Like most human activities, ballooning has sponsored heroes and hucksters and a good deal in between. For every dedicated scientist patiently recording atmospheric pressure and wind speed while shivering at high altitudes, there is a carnival barker with a bevy of pretty girls willing to dangle from a basket or parachute down to earth.

in between

1. Between
2. In the space between

• inbetweening