1. 
[syn: craftily, cunningly, foxily, knavishly, slyly, trickily, artfully]
The Collaborative International Dictionary of English v.0.48:
Knavishly \Knav"ish*ly\, adv.
   1. In a knavish manner; dishonestly; fraudulently. --Holland.
      [1913 Webster]
   2. Mischievously; waggishly; roguishly. "Knavishly witty."
      --Gayton.
      [1913 Webster]
WordNet (r) 3.0 (2006):
knavishly
    adv 1: in an artful manner; "he craftily arranged to be there
           when the decision was announced"; "had ever circumstances
           conspired so cunningly?" [syn: craftily, cunningly,
           foxily, knavishly, slyly, trickily, artfully]