The Collaborative International Dictionary of English v.0.48:
Wilful \Wil"ful\, a., Wilfully \Wil"ful*ly\, adv., Wilfulness \Wil"ful*ness\, n. See Willful, Willfully, and Willfulness. [1913 Webster]WordNet (r) 3.0 (2006):
wilfully adv 1: in a willful manner; "she had willfully deceived me" [syn: willfully, wilfully]