combust
Intermediate (B1)
IPA: /kəmˈbʌst/
KK: /kəmˈbʌst/
intransitive verb
Definition
To catch fire or burn suddenly without an external flame; to undergo a chemical reaction that produces heat and light.
Example
The old rags in the corner spontaneously combusted, causing a small fire.
Tense Forms
Past: combusted
Past Participle: combusted
Conversation
Did you hear about the fire at the old factory?
Yeah, I heard it was crazy how quickly things combust there.
Right? It must have been some dangerous materials involved.
Definitely, I can't believe no one got hurt.
Synonyms & Antonyms
Synonyms
ignite
flare
burn
Antonyms
extinguish
douse
quench
transitive verb
Definition
To cause something to burn or ignite.
Example
The dry leaves combusted quickly when the fire started.
Tense Forms
Past: combusted
Past Participle: combusted
Conversation
Have you ever seen a campfire combust into a huge flame?
Yeah, it’s pretty amazing how quickly it can happen.
It’s wild how just a little spark can combust all that wood.
Root Explanation
Combust is formed from "com-" (meaning together) and "burere" (meaning to burn). The word describes the process of burning together or the state of being burned.
Memory Tip
Think of things 'burning together' — 'com-' means together, and 'burere' means to burn.
Visually Confused Words
comus
cobus
colymbus