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.
It was blamed in part on the building’s highly flammable cladding and lack of alarms, sprinklers and a fire escape.
From The Wall Street Journal ● Jul. 20, 2026
Busakorn also noted that the stage was decorated using highly flammable materials such as plastic flowers, while the ceiling was plastered with combustible foam.
From BBC ● Jul. 14, 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
There has been some speculation online that the spheres are propellant tanks for spacecraft, and so could contain residual amounts of a highly flammable or reactive substance.
From BBC ● Jul. 5, 2026
The stronger structure might buy them more time, but it also meant that an even larger cloud of flammable gas was building up.
From "Meltdown" by Deirdre Langeland
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.
