Source : Webster's Revised Unabridged Dictionary (1913)

Sarcasm \Sar"casm\, n. [F. sarcasme, L. sarcasmus, Gr.
   sarkasmo`s, from sarka`zein to tear flesh like dogs, to bite
   the lips in rage, to speak bitterly, to sneer, fr. sa`rx,
   sa`rkos, flesh.]
   A keen, reproachful expression; a satirical remark uttered
   with some degree of scorn or contempt; a taunt; a gibe; a
   cutting jest.

         The sarcasms of those critics who imagine our art to be
         a matter of inspiration.                 --Sir J.
                                                  Reynolds.

   Syn: Satire; irony; ridicule; taunt; gibe.

Source : WordNet®

sarcasm
     n : witty language used to convey insults or scorn; "he used
         sarcasm to upset his opponent"; "irony is wasted on the
         stupid"; "Satire is a sort of glass, wherein beholders do
         generally discover everybody's face but their
         own"--Johathan Swift [syn: {irony}, {satire}, {caustic
         remark}]