perfidiously

from WordNet (r) 3.0 (2006)
perfidiously
    adv 1: in a perfidious manner; "he was playing perfidiously one
           side against the other"
from The Collaborative International Dictionary of English v.0.48
Perfidiously \Per*fid"i*ous*ly\, adv.
   In a perfidious manner.
   [1913 Webster]
antiflux / dictionary / perfidiously
[email protected]