Origin: 1595–1605; Related forms
< Medieval Latin inflammābilis,
equivalent to Latin inflammā
) to inflame
+ -bilis -ble
in·flam·ma·bil·i·ty, in·flam·ma·ble·ness, noun
2. fiery, volatile, choleric.
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.