handback

Presumably from the verb hand +‎ back

handback (plural handbacks)

1. The act of handing something back.
   • 2019 October, Tony Miles, Philip Sherratt, “EMR kicks off new era”, in Modern Railways, page 59:

     'Route director Gary Walsh and I will be refreshing the meeting structures and we are already looking much more at passenger issues and areas like late handbacks of possessions.'

In the British rail industry this appears to relate to handing back a railway line after an engineering possession, where the line has to be closed for work to be carried out.

• back-hand, backhand