to move counters into the inner board
To bring your checkers into your inner board in preparation for the bearoff. You will have a slow board if you choose to bear in all your checkers to the 6 pt.
This is one of backgammon rules that says - bring the checkers home BEFORE you can take them out (bear them off).
Bear in means that you move one of your checkers into your home board. It is a step before all of your checkers are gathered and you begin to bear them off (take them out of the board).
Moving one's checkers into one's inner board as the step before bearing off.
To bring a man into your home board prior to bearing off.