Combusting

Part of speech: verb

Definitions

1. Experiencing the chemical process of burning with flame or heat
2. Being in the state of ignition where a substance reacts rapidly with oxygen
3. Undergoing rapid oxidation that produces heat and light in the form of fire

Etymology: The verb "combust" came into English from Latin through Middle English, and its story starts with a Latin verb meaning to burn up completely. "Combustus" is the past participle of "combūrere," which joins "com-" (an intensifying prefix, roughly "altogether") to "ūrere," "to burn." The Latin sense was thorough destruction by fire, the idea of something being consumed entirely. The word passed into Middle English as "combust," meaning "burnt," by way of Middle French. For a long time it stayed a transitive verb, meaning someone or something set something else alight, and the sense of a substance catching fire on its own came later. The "-ing" form you see here is simply the present participle of this verb, used in its modern intransitive sense of a material reacting rapidly with oxygen and igniting.

Synonyms: burning, igniting, flaming, blazing, incinerating

Antonyms: extinguishing, quenching, dousing, suppressing, smothering