A salvo is when troops fire their guns all at the same time. A salvo of shots might signal the beginning of a military battle.
Another word for the gunfire kind of salvo is a “volley.” Military planners have used salvos as a way to overwhelm an opposing army, including during engagements between battleships and tanks. You can also use salvo in a more figurative way, describing a verbal barrage or attack: “Her direct, almost rude questions were seen as the opening salvo in the battle between the two political candidates.”
rapid simultaneous discharge of firearms
an outburst resembling the discharge of firearms or the release of bombs
a sudden outburst of cheers