What does Boombardment mean?

Boombardment meaning in Urban Dictionary

A Boombardment is when you drop down on the residual survivors, as a boomer, in Left 4 lifeless or Left 4 Dead 2. this can come out as a massive surge of boomer bile, which draws the horde.A Boombardment is a great tactical move if your move is reasonable on health and it going to die anyway.