What figure of speech does under the gun mean?

Answer 1

Type your answer here... In military parlance, under the gun means to get closer to the guns then their range allows them to adjust downward. If you are under the gun, they cannot lower the cannons low enough to hit you, as they will hit the ground instead. You are "under the gun" when the military heavy artillery cannot hit you and you are therefore able to take out the cannons with small arms fire by getting up close enough to shoot the gunner.