Going over the top
-
A phrase used during World War I to describe men [climbing out] of their [trenches] to attack the opposing trenches. Before running into a wall of rifle and machine gun fire, the attackers were usually given a [warm meal], a bit of rum, and said potential goodbyes to each other before facing almost certain death. It was considered the greatest test a man could ever face.
Going over the top meaning & definition 1 of Going over the top.