def·​la·​grate ˈde-flə-ˌgrāt How to pronounce deflagrate (audio)
deflagrated; deflagrating

transitive verb

: to cause to deflagrate compare detonate sense 1

intransitive verb

: to burn rapidly with intense heat and sparks being given off
deflagration noun

Did you know?

Deflagrate combines the Latin verb flagrare, meaning "to burn," with the Latin prefix de-, meaning "down" or "away." Flagrare is also an ancestor of such words as conflagration and flagrant and is distantly related to fulgent and flame. In the field of explosives, deflagrate is used to describe the burning of fuel accelerated by the expansion of gasses under the pressure of containment, which causes the containing vessel to break apart. In comparison, the term detonate (from the Latin tonare, meaning "to thunder") refers to an instant, violent explosion that results when shock waves pass through molecules and displace them at supersonic speed. Deflagrate has been making sparks in English since about 1727, and detonate burst onto the scene at around the same time.

Word History


Latin deflagratus, past participle of deflagrare to burn down, from de- + flagrare to burn — more at black entry 1

First Known Use

circa 1727, in the meaning defined at transitive sense

Time Traveler
The first known use of deflagrate was circa 1727


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Cite this Entry

“Deflagrate.” Dictionary, Merriam-Webster, Accessed 24 Apr. 2024.

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