capable of being set on fire; combustible; flammable.
easily aroused or excited, as to passion or anger; irascible: an inflammable disposition.


something inflammable.

Origin of inflammable

1595–1605; < Medieval Latin inflammābilis, equivalent to Latin inflammā(re) to inflame + -bilis -ble
Related formsin·flam·ma·bil·i·ty, in·flam·ma·ble·ness, nounin·flam·ma·bly, adverbnon·in·flam·ma·bil·i·ty, nounnon·in·flam·ma·ble, adjectivenon·in·flam·ma·ble·ness, nounnon·in·flam·ma·bly, adverbun·in·flam·ma·bil·i·ty, nounun·in·flam·ma·ble, adjective
Can be confusedinflammable inflammatory

Synonyms for inflammable

Usage note

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. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for inflammability

Historical Examples of inflammability

  • It is also used in fireworks on account of its inflammability.

    Commercial Geography

    Jacques W. Redway

  • We find that it differs in respect to its purity, and also in respect to its inflammability.

  • Its inflammability is, of course, a serious obstacle to its general use.


    Thomas Wright Jackson

  • Besides this, petroleum is highly dangerous on account of its inflammability.

  • Apparently unknown to Murdock, previous observations had been made as to the inflammability of gas from coal.

    Artificial Light

    M. Luckiesh

British Dictionary definitions for inflammability



liable to catch fire; flammable
readily aroused to anger or passion


something that is liable to catch fire
Derived Formsinflammability or inflammableness, nouninflammably, adverb


Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for inflammability



early 15c., in medicine, "liable to inflammation," from Middle French inflammable and directly from Medieval Latin inflammabilis, from Latin inflammare (see inflame). As "able to be set alight," c.1600. Related: Inflammability.

Online Etymology Dictionary, © 2010 Douglas Harper