So you are talking about a detonation, a specific type of explosion that involves a supersonic wave, almost everything you would see as a munitions expert would be one of those.

A dictionary definition of explosion is "a rapid expansion in volume associated with extreme outward release of energy", that includes things like, gunpowder deflagration, aerolized gasoline burning, or even a pressurized container (like a pressure cooker) rupturing. Film burning on a metal tin as they were stored could fit this definition pretty well.