Nefarious, a.
Etymology: [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.
Syn. -- Iniquitous; detestable; horrible; heinious; atrocious; infamous; impious. See Iniquitous. -- Ne*fa"ri*ous*ly, adv. -- Ne*fa"ri*ous*ness, n.
Shades of meaning
Fernald has no entry of its own for nefarious; he lists it under criminal.
He lists it without comment; the entries above explain its neighbors.