WordWeb Online

1. Internal to, involving members of (a group of people)
   "they argued between themselves"
   - among, amongst, within
    
2. In division, with shares to each
   "the top leadership divides the spoils between themselves"
   - among, amongst

1. In the interval
   "dancing all the dances with little rest between"
   - betwixt [archaic]
    
2. In between
   "two houses with a tree between"
   - 'tween

Encyclopedia: Between Between, GA Between, Georgia