Origin: 1595–1605; < L nefārius wicked, vile, equiv. to nefās offense against divine or moral law (ne- negative prefix + fās law, right) + -ius-ious, with intervocalic s > r
ne·far·i·ous (nə-fâr'ē-əs) adj. Infamous by way of being extremely wicked.
[Latin nefārius, from nefās, crime, transgression : ne-, not; see ne in Indo-European roots + fās, divine law; see dhē- in Indo-European roots.] ne·far'i·ous·ly adv., ne·far'i·ous·ness n.
1604, from L. nefarius "wicked, abominable," from nefas "crime, wrong, impiety," from ne- "not" (see un-) + fas "right, lawful, divinely spoken," related to fari "to speak" (see fame).