The Collaborative International Dictionary
Mordaciously
Mordacious \Mor*da"cious\, a. [L. mordax, -acis, fr. mordere, morsum, to bite. See Morsel.] Biting; given to biting; hence, figuratively, sarcastic; severe; scathing. -- Mor*da"cious*ly, adv.
WordNet
mordaciously
adv. in a mordacious manner; "she taunted him mordaciously"