The Collaborative International Dictionary of English v.0.48:
Dubiously \Du"bi*ous*ly\, adv. In a dubious manner. [1913 Webster]WordNet (r) 3.0 (2006):
dubiously adv 1: in a questionable and dubious manner; "these were estates his father questionably acquired" [syn: questionably, dubiously] 2: in a doubtful manner; "Gerald shook his head doubtfully" [syn: doubtfully, dubiously]