firing (n.)
1540s, "action of applying fire or setting on fire," verbal noun from fire (v.). From c. 1600 as "act of discharging firearms." Firing squad is attested from 1891 in reference to military executions; earlier as "those selected to fire over the grave of anyone interred with military honors" (1864); earlier in both senses is firing-party (1798 in reference to military executions; 1776 in reference to military funerals).