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
- flammability noun
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.
For example, when pure lithium comes into contact with water, it produces heat and releases hydrogen gas, which is extremely flammable.
From Science Daily • Apr. 16, 2026
County Fire Chief Anthony Marrone that killing off the deer — which reduce flammable material through grazing — could increase wildfire risk.
From Los Angeles Times • Feb. 3, 2026
"He did not want to install a highly flammable foam. He wanted to install acoustic foam," he said.
From BBC • Jan. 19, 2026
In 2015, blasts at warehouses containing flammable chemicals in the port city of Tianjin killed more than 170 people and injured 700 others.
From Barron's • Jan. 18, 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.
