Fromrun +‎back.

runback (pluralrunbacks)

1. (American football) The act of returning a kicked ball, such as from apunt orkickoff
   • 1936 October 18, “Fifty Yard Runback of Punt Gives Bowdoin 6-0 Win Over Williams”, inHartford Courant‎^[1], archived fromthe original on30 June 2013, page C4:

     A fifty yardrunback of a punt by Jack Reed in the fourth period gave Bowdoin a 6-0 win over Williams today in a driving rain.

2. A managedreduction ofoutput in apower plant.

• run back
• running back

• backrun