Detonation

Noun

1. An explosion or sudden report made by the near-instantaneous decomposition or combustion of unstable substances. Specifically, combustion that spreads supersonically via shock compression.

   "the detonation of gun cotton"

2. Any sudden explosion made by an exothermic process (whether chemical or not) that produces a supersonic shock wave.

   "a nuclear detonation"

3. Engine knocking, a type of improper combustion in gasoline piston engines.