The Collaborative International Dictionary of English v.0.48:
Inaccurately \In*ac"cu*rate*ly\, adv. In an inaccurate manner; incorrectly; inexactly. [1913 Webster]WordNet (r) 3.0 (2006):
inaccurately adv 1: in an inaccurate manner; "this student works rather inaccurately and sloppily" [ant: accurately]