■ adjective easily set on fire.
■ noun a substance which is easily set on fire.
Derivatives
inflammability noun
~ness noun
inflammably adverb
Usage
The words ~ and flammable both mean ‘easily set on fire’. Inflammable is formed using the Latin prefix in- which has the meaning ‘into’ (rather than the more common use of in- to indicate negation), and here has the effect of intensifying the meaning of the word in English.