Definition of nefariousnext
as in evil
not conforming to a high moral standard; morally unacceptable the chaste heroines and nefarious villains of old-time melodramas

Synonyms & Similar Words

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Antonyms & Near Antonyms

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How does the adjective nefarious differ from other similar words?

Some common synonyms of nefarious are corrupt, degenerate, iniquitous, vicious, and villainous. While all these words mean "highly reprehensible or offensive in character, nature, or conduct," nefarious suggests flagrant breaching of time-honored laws and traditions of conduct.

the nefarious rackets of organized crime

Where would corrupt be a reasonable alternative to nefarious?

While in some cases nearly identical to nefarious, corrupt stresses a loss of moral integrity or probity causing betrayal of principle or sworn obligations.

city hall was rife with corrupt politicians

When could degenerate be used to replace nefarious?

In some situations, the words degenerate and nefarious are roughly equivalent. However, degenerate suggests having sunk to an especially vicious or enervated condition.

a degenerate regime propped up by foreign powers

When can iniquitous be used instead of nefarious?

The words iniquitous and nefarious are synonyms, but do differ in nuance. Specifically, iniquitous implies absence of all signs of justice or fairness.

an iniquitous system of taxation

When might vicious be a better fit than nefarious?

The meanings of vicious and nefarious largely overlap; however, vicious may directly oppose virtuous in implying moral depravity, or may connote malignancy, cruelty, or destructive violence.

a vicious gangster

When would villainous be a good substitute for nefarious?

While the synonyms villainous and nefarious are close in meaning, villainous applies to any evil, depraved, or vile conduct or characteristic.

a villainous assault

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of nefarious These are among at least 10 individuals connected to sensitive US nuclear and aerospace research who have died or disappeared in recent years, prompting concerns whether they are connected and fueling speculation online about the possibility of nefarious activity. Natasha Chen, CNN Money, 21 Apr. 2026 Like every technological innovation AI going to be used for virtuous and nefarious things, but in terms of criminal activity experts say the scale and sophistication of fraud has accelerated. Phillip M. Bailey, USA Today, 17 Apr. 2026 The new season explores child stars gone bad, the death of Prince, nefarious celebrity doctors, The Jerry Springer Show, and more. K. Thor Jensen, PC Magazine, 17 Apr. 2026 When a technology company does it, the assumption is more nefarious. Jonathan Hunt, Fortune, 11 Apr. 2026 See All Example Sentences for nefarious
Recent Examples of Synonyms for nefarious
Adjective
  • The actors sprang to life, staging a lurid scene in which an evil mistress named Selina frames the heroine for killing her unborn child.
    Chang Che, New Yorker, 25 Apr. 2026
  • Clearly, the Iranian regime is evil.
    Tom Jurkowsky, Baltimore Sun, 25 Apr. 2026
Adjective
  • Van Dyke, who is stationed at Fort Bragg near Fayetteville, North Carolina, was charged Thursday with the unlawful use of confidential government information for personal gain, theft of nonpublic government information, commodities fraud, wire fraud and making an unlawful monetary transaction.
    Gary D. Robertson, Chicago Tribune, 24 Apr. 2026
  • He has been charged in New York federal court with unlawful use of confidential government information for personal gain, theft of nonpublic government information, commodities fraud, wire fraud and making an unlawful monetary transaction.
    Erik Ortiz, NBC news, 24 Apr. 2026
Adjective
  • Pope Francis changed the church’s social teaching to declare capital punishment immoral in all cases.
    Nicole Winfield, Fortune, 23 Apr. 2026
  • For him, in becoming photosynthetic, civilized beings would only gain in hallmarks of intelligence, like autonomy and compassion, given that a species living off starlight converts energy to work without the messy, immoral mediation of a food chain.
    Big Think, Big Think, 22 Apr. 2026
Adjective
  • Christian moralists thundered against the sinful pleasures of watching naked female flesh at the Spectacles.
    Literary Hub, Literary Hub, 15 Apr. 2026
  • His father, who believes Sammie's music to be sinful, orders him to drop the guitar, but Sammie can't do it.
    Randall Colburn, Entertainment Weekly, 12 Mar. 2026
Adjective
  • Now, is that the same as a soldier betting on the capture of a vicious dictator?
    Zach Dean OutKick, FOXNews.com, 24 Apr. 2026
  • Beijing has long struggled to drive domestic consumption, while brutal competition in many industries has pushed producers to cut prices, triggering a vicious cycle in which people hold off on purchases in anticipation of coming discounts.
    Jeronimo Gonzalez, semafor.com, 23 Apr. 2026
Adjective
  • The bleak tortures Ohm concocts for his characters are as vile as the Bilberry’s fetid jacuzzi.
    Amy Nicholson, Los Angeles Times, 30 Apr. 2026
  • There’s something vile, yet attractive about the film, an encapsulation of the fact that people and the internet are downright weird.
    Richard Newby, HollywoodReporter, 27 Apr. 2026
Adjective
  • But what exactly happens to these baby stars next isn't always clear (literally) because they are buried deep within clouds of dark, dusty gas that obscure them.
    Keith Cooper, Space.com, 28 Apr. 2026
  • All the bedrooms can be found upstairs, including one that’s currently being used as an office and a primary suite flaunting dual dressing rooms and baths, plus a sauna clad in dark gray stone.
    Wendy Bowman, Robb Report, 28 Apr. 2026
Adjective
  • Its 28-game start matches the expansion 1962 Mets — who lost 120 games — along with 1964 and 1983 for the second-worst in team history behind an 8-20 opening in 1981.
    Ronald Blum, Chicago Tribune, 27 Apr. 2026
  • Ossai isn’t a bad pass rusher either, getting five sacks in each of the last two seasons, a total that somehow would’ve ranked second on the Jets last season.
    Zack Rosenblatt, New York Times, 27 Apr. 2026

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Cite this Entry

“Nefarious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/nefarious. Accessed 1 May. 2026.

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