The Collaborative International Dictionary of English v.0.48:
Fantastically \Fan*tas"tic*al*ly\, adv. In a fantastic manner. [1913 Webster] the letter A, in scarlet, fantastically embroidered with gold thread, upon her bosom. --Hawthorne. [1913 Webster]WordNet (r) 3.0 (2006):
fantastically adv 1: exceedingly; extremely; "she plays fabulously well" [syn: fabulously, fantastically, incredibly]