flammable
Americanadjective
adjective
Usage
Flammable and inflammable are interchangeable when used of the properties of materials. Flammable is, however, often preferred for warning labels as there is less likelihood of misunderstanding ( inflammable being sometimes taken to mean not flammable ). Inflammable is preferred in figurative contexts: this could prove to be an inflammable situation
Commonly Confused
See inflammable.
Other Word Forms
Etymology
Origin of flammable
First recorded in 1805–15; from Latin flammā(re) “to set on fire” + -ble
Explanation
Be careful with matches around gasoline, dry grass, and old wood because they are all very flammable and might catch on fire. Flammable is a pretty straightforward word with one odd fact about it. The word, inflammable, which sounds like the opposite of flammable, actually means the same thing — easily catching on fire. If you want to say that something won't catch fire easily, use fireproof and you'll be sure to be right.
Vocabulary lists containing flammable
Power Suffix: -able
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List 6
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Hatchet
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The fierce fires ravaging parts of France and Spain are the result of forests and vegetation becoming more flammable because of drought and a series of record-breaking heatwaves that have hit Western Europe since May.
From Barron's ● Jul. 25, 2026
According to a report by the government news agency Andina, external, neighbours said unknown individuals had set fire to motorcycles parked outside, with the flames spreading rapidly through flammable mattress-making materials.
From BBC ● Jul. 22, 2026
Highly flammable when treated with acid, it acts as a propellant, triggering a violent expansion of gas needed to launch artillery up to 70 miles.
From The Wall Street Journal ● Jul. 20, 2026
The forest sees 15 million visitors each year, making it vulnerable to fires -- quite apart from its sandy soil and vegetation consisting of ferns and highly flammable conifers.
From Barron's ● Jul. 14, 2026
But food, by its very nature, contained flammable hydrocarbons.
From "The Martian" by Andy Weir
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
