extremely wicked or villainous; iniquitous: a nefarious plot.

Origin of nefarious

1595–1605; < Latin nefārius wicked, vile, equivalent to nefās offense against divine or moral law (ne- negative prefix + fās law, right) + -ius -ious, with intervocalic s > r
Related formsne·far·i·ous·ly, adverbne·far·i·ous·ness, nounun·ne·far·i·ous, adjectiveun·ne·far·i·ous·ly, adverbun·ne·far·i·ous·ness, noun

Synonyms for nefarious

Antonyms for nefarious Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for nefarious

Contemporary Examples of nefarious

Historical Examples of nefarious

  • Nay, they are neither; but, nevertheless, their errand is a nefarious one.

  • They were probably out on the trail pursuing their nefarious calling.

  • Might she not be the tool, consciously or unconsciously, of a nefarious plot?

    The Crevice

    William John Burns and Isabel Ostrander

  • It is the duty of patriotic Swedes to thwart this nefarious project.

    England and Germany

    Emile Joseph Dillon

  • Let us see then if you'll dare to persist in this nefarious scheme.

    Arthur O'Leary

    Charles James Lever

British Dictionary definitions for nefarious



evil; wicked; sinful
Derived Formsnefariously, adverbnefariousness, noun

Word Origin for nefarious

C17: from Latin nefārius, from nefās unlawful deed, from not + fās divine law
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for nefarious

c.1600, from Latin nefarius "wicked, abominable, impious," from nefas "crime, wrong, impiety," from ne- "not" (see un-) + fas "right, lawful, divinely spoken," related to fari "to speak" (see fame (n.)). Related: Nefariously.

Online Etymology Dictionary, © 2010 Douglas Harper