inflammable

American  

[in-flam-uh-buhl] / ɪnˈflæm ə bəl /

adjective

1. capable of being set on fire; combustible; flammable.

2. easily aroused or excited, as to passion or anger; irascible.

   an inflammable disposition.

   Synonyms:

   choleric, volatile, fiery

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noun

1. something inflammable.

inflammable British  

/ ɪnˈflæməbəl /

adjective

1. liable to catch fire; flammable

2. readily aroused to anger or passion

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noun

1. something that is liable to catch fire

Commonly Confused

Inflammable and flammable both mean “combustible.” Inflammable is the older by about 200 years. Flammable now has certain technical uses, particularly as a warning on vehicles carrying combustible materials, because of a belief that some might interpret the intensive prefix in- of inflammable as a negative prefix and thus think the word means “noncombustible.” Inflammable is the word more usually used in nontechnical and figurative contexts: The speaker ignited the inflammable emotions of the crowd.

Other Word Forms

• inflammability noun
• inflammableness noun
• inflammably adverb
• noninflammability noun
• noninflammable adjective
• noninflammableness noun
• noninflammably adverb
• uninflammability noun
• uninflammable adjective

Etymology

Origin of inflammable

1595–1605; < Medieval Latin inflammābilis, equivalent to Latin inflammā ( re ) to inflame + -bilis -ble

Explanation

Something that is inflammable can be set on fire easily. You dared not light a match after you accidentally spilled gasoline on yourself because you knew you were inflammable. Inflammable can be a tricky word, since the in- prefix often means "not." But in this case, the in- isn't really a prefix, because the word is built from the verb inflame which means "to set on fire." Some inflammable things might literally go up in flames, but we also use it metaphorically. Someone with a quick temper could be described as "inflammable," and if you fall in love easily, then you have an inflammable heart.

Example Sentences

Many in Iran are blaming the authorities for incompetence and worse, asking: How could so much inflammable material apparently be left on the port without due care?

From BBC • Apr. 27, 2025

In addition, they contain no easily inflammable liquids.

From Science Daily • Oct. 23, 2023

“This is not normal, of course. This is a very volatile, very inflammable situation,” said Artyom Shraibman, founder of Sense Analytics and a Belarus analyst with the Carnegie Moscow Center think tank.

From Washington Post • Nov. 17, 2021

“All four were driven, visionary men, all were caught up in the issues of slavery and race, and all devised their own solutions to those inflammable problems,” he wrote.

From Seattle Times • Aug. 26, 2021

Besides, the cables, the pylons, the transformers were too close: to be swept in among them, with a zeppelin full of inflammable gas, would be instantly fatal.

From "The Amber Spyglass" by Philip Pullman