The Collaborative International Dictionary of English v.0.48:
Fashionably \Fash"ion*a*bly\, adv. In a fashionable manner. [1913 Webster]WordNet (r) 3.0 (2006):
fashionably adv 1: in a fashionable manner; "his voice had no trace of the drawl that you would expect to find in a fashionably dressed young man" [ant: unfashionably]