What term is used to describe a bursting inward?

The term that describes a bursting inward is "implosion." This word specifically refers to the act of collapsing inward under external pressure or as a result of a sudden loss of structural integrity. In various contexts, such as engineering or physics, implosions occur when the internal pressure of an object decreases significantly, leading to the walls or surfaces of that object to collapse inwardly, often dramatically.

On the other hand, concepts like explosion and detonation refer to bursts that occur outward, where energy is released rapidly, often resulting in destructive force traveling away from the origin. "Collapse" can describe a failure to maintain structure but does not specifically denote an inward bursting. Therefore, "implosion" is the precise term for the phenomenon of bursting inward, making it the correct choice.