Source : Webster's Revised Unabridged Dictionary (1913)

Combustible \Com*bus"ti*ble\, a. [Cf. F. combustible.]
   1. Capable of taking fire and burning; apt to catch fire;
      inflammable.

            Sin is to the soul like fire to combustible matter.
                                                  --South.

   2. Easily kindled or excited; quick; fiery; irascible.

            Arnold was a combustible character.   --W. Irving.

Combustible \Com*bus"ti*ble\, n.
   A substance that may be set on fire, or which is liable to
   take fire and burn.

         All such combustibles as are cheap enough for common
         use go under the name of fuel.           --Ure.

Source : WordNet®

combustible
     adj : capable of igniting and burning [ant: {noncombustible}]

combustible
     n : a substance that can be burned to provide heat or power
         [syn: {combustible material}]