nefariously

from WordNet (r) 3.0 (2006)

nefariously
    adv 1: in a nefarious manner or to a nefarious degree;
           "nefariously involved in a conspiracy"

from The Collaborative International Dictionary of English v.0.48

Nefarious \Ne*fa"ri*ous\, a. [L. nefarius, fr. nefas crime,
   wrong; ne not + fas divine law; akin to fari to speak. See
   {No}, adv., and {Fate}.]
   Wicked in the extreme; abominable; iniquitous; atrociously
   villainous; execrable; detestably vile.
   [1913 Webster]

   Syn: Iniquitous; detestable; horrible; heinious; atrocious;
        infamous; impious. See {Iniquitous}.
        [1913 Webster] -- {Ne*fa"ri*ous*ly}, adv. --
        {Ne*fa"ri*ous*ness}, n.
        [1913 Webster]