adj.
 easily set on fire.
n.
 a substance which is easily set on fire.
Derivative
  
    - inflammability n.
- inflammableness n.
- inflammably adv.
 
  Usage
  The words inflammable 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.