combustion

noun

com·​bus·​tion kəm-ˈbəs-chən 

1

: an act or instance of burning

Smoke is produced during combustion.

2

: a usually rapid chemical process (such as oxidation) that produces heat and usually light

The carburetor mixes fuel with air for combustion.

also : a slower oxidation (as in the body)

3

: violent agitation : tumult

… periods of great social combustion alternating with quiescence …

—Kurt Andersen

combustive

kəm-ˈbə-stiv 

adjective

Examples of combustion in a Sentence

Combustion may occur at high temperatures.

This ratio of air to fuel results in better combustion.

Recent Examples on the Web

Jung said interest has been high since the Leaf launched in the fall, with 70% of customers trading in their internal combustion or hybrid vehicles for a Leaf. —Morgan Korn, ABC News, 21 Dec. 2025

The company specializes in electrifying iconic vehicles—among them the Porsche 911 (964), Land Rover Series IIA, Mercedes-Benz W113 Pagoda, and Ford GT40—by replacing their internal combustion powertrains with bespoke electric systems while preserving the vehicles’ original driving character. —Paul Ratner, Interesting Engineering, 17 Dec. 2025

That said, the standard internal-combustion-engine version of the Snowdog is old news, as it's been in production for the past 10 years. —New Atlas, 17 Dec. 2025

Picture Alliance | Picture Alliance | Getty Images The European Union on Tuesday is expected to water down its effective ban on sales of new combustion-engine cars from 2035, after lobbying efforts from Germany, Italy, and some automotive industry groups. —Sam Meredith, CNBC, 16 Dec. 2025

Word History

Etymology

Middle English combustioun "burning, calcination," borrowed from Anglo-French & Late Latin; Anglo-French combustion, borrowed from Late Latin combustiōn-, combustiō "burning up (of the dead or by the fires in hell)," from Latin combus-, variant stem of combūrere "to destroy with fire, reduce to ashes" + -tiōn-, tiō, suffix of verbal action — more at combust

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing combustion

• combustion chamber
• combustion engine
• external combustion engine
• internal combustion engine
• pre-combustion
• spontaneous combustion

Rhymes for combustion

• fustian

Kids Definition

combustion

noun

com·​bus·​tion kəm-ˈbəs-chən 

1

: an act or instance of burning

2

: a chemical process in which substances combine with oxygen

Medical Definition

combustion

noun

com·​bus·​tion kəm-ˈbəs-chən 

: a usually very rapid chemical process (as oxidation) that produces heat and usually light

also : a slower oxidation (as in the body)