Source : Webster's Revised Unabridged Dictionary (1913)

Sarcastically \Sar*cas"tic*al*ly\, adv.
   In a sarcastic manner.

Source : WordNet®

sarcastically
     adv : in a sarcastic manner; "`Ah, now we're getting at the
           truth,' he interposed sarcastically" [syn: {sardonically}]