Black Hole Bomb is the name of a physical effect that uses the way a bosonic field hitting a rotating black hole can be amplified by superradiant scattering. If the boosted field is reflected back into the black hole, the boost can be repeated, leading to an uncontrolled increase in the field, i.e. an explosion. One of the ways to make this reflection in nature is through the presence of mass in the bosonic field. Then the field mass can cause the amplified mods to become trapped around the black hole, leading to an endless cycle of self-amplification.
The mechanism of a black hole bomb is called superradiant scattering. It could also refer to one such method of creating this escape effect, a Penrose sphere without the ability to release passive energy.