deflagration
Pronunciation: /dɛfləˈɡreɪʃ(ə)n/
noun
- the action of heating a substance until it burns away rapidly.
- technical combustion which propagates through a gas or across the surface of an explosive at subsonic speeds, driven by the transfer of heat. Compare with detonation.

Origin:
early 17th century: from Latin deflagratio(n-), from the verb deflagrare (see deflagrate)