adjective
flammable
FLA-muh-buhl
adjective
1
Capable of catching fire easily.
"Gasoline is highly flammable, so store it away from any heat source."
2
(informal) Likely to spark an argument or controversy.
"That's a flammable topic to bring up at a family dinner."
How to Use Flammable
Learner’s notesIn plain EnglishSomething that catches fire easily.
Common mistake
Flammable and inflammable mean the same thing — the in- in inflammable is not a negative prefix here, even though it looks like one. Safety labels now favor "flammable" and "non-flammable" to avoid confusion.
Easily confused with
inflammable
Word Forms
more flammable comparative, flammables plural, most flammable superlative
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Gasoline is highly _____, so store it away from any heat source.
Etymology
Formed as a back-formation from inflammable, deliberately created so warning labels wouldn't be misread as meaning "not flammable."