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
Derived 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.
This may have led to a buildup of heat in a pressurized tank filled with 7,000 gallons of a chemical called methyl methacrylate, a highly flammable liquid monomer used to manufacture plastics.
From Los Angeles Times • May 26, 2026
The tank in southern California contains an estimated 7,000 gallons of methyl methacrylate, a highly volatile and flammable substance used in the production of plastic.
From BBC • May 23, 2026
Researchers, who combined fieldwork with satellite data, suggested that "unusually dry conditions" and "flammable vegetation" enabled the fire to burn deep peat soils.
From BBC • May 21, 2026
That industry research notably includes a recommendation to clear all flammable material within the first five feet of homes in high-risk areas, including trees, plants, grasses and wooden fences.
From Los Angeles Times • May 20, 2026
Second, all highly flammable material inside the spacecraft had to be replaced.
From "Flying to the Moon: An Astronaut's Story" by Michael Collins
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.
