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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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 Captain Jonathan Baxter told PEOPLE that the surfer's death was not caused by anything nefarious. Charna Flam, PEOPLE, 29 May 2026 LLMs can be poisoned and forced to hallucinate, or they can also be jailbroken and used for nefarious purposes. Tom Kellermann, Forbes.com, 28 May 2026 And Dart’s teammate Abdul Carter took issue with his QB’s public support of the nefarious president. Pat Leonard, New York Daily News, 23 May 2026 There were some pretty nefarious characters with criminal records. Stephanie Nolasco, FOXNews.com, 23 May 2026 See All Example Sentences for nefarious
Recent Examples of Synonyms for nefarious
Adjective
  • This is a story devoid of childlike wonder, just the horrific evil men are capable of and the small acts of grace found in unspeakable circumstances.
    Chris Nashawaty, Entertainment Weekly, 13 June 2026
  • Nicholas Galitzine stars as the muscular hero in the new version, which also features Idris Elba as Man-at-Arms Duncan, Camila Mendes as Teela and Jared Leto as the evil wizard Skeletor.
    Tim Lammers, Forbes.com, 12 June 2026
Adjective
  • What happens if a landlord charges an unlawful late fee?
    Tiffani Jackson, Fort Worth Star-Telegram, 12 June 2026
  • London’s High Court ruled that the decision to proscribe the group was unlawful, but has kept the ban in place pending an appeals court ruling due Monday.
    ABC News, ABC News, 12 June 2026
Adjective
  • Religious practitioners may also regard nonheterosexual orientations or non-cisgender identities as immoral or otherwise inconsistent with their religious beliefs.
    Britannica Editors, Encyclopedia Britannica, 10 June 2026
  • Republicans, grow a spine and stop the immoral president.
    Voice of the People, New York Daily News, 10 June 2026
Adjective
  • Bowing down and worshiping an idol is sinful.
    Lauren Costantino, Miami Herald, 12 May 2026
  • Efficiency is religion, and turnovers are almost sinful.
    Joel Lorenzi, New York Times, 6 May 2026
Adjective
  • The tabloids have been extra vicious of late regarding your family strife.
    Marlow Stern, Variety, 12 June 2026
  • Firefighters faced vicious winds and, at times, 30-foot flames.
    Jaclyn Cosgrove, Los Angeles Times, 11 June 2026
Adjective
  • While Washington drags its feet, kids across the nation are being exposed to vile, pornographic images and ads with no meaningful safeguards to prevent it.
    Rachel del Guidice, FOXNews.com, 10 June 2026
  • Maddie Scott reposted vile comments from one user in particular that threatened not only her and her husband, but also their newborn son.
    Steve Henson, Los Angeles Times, 1 June 2026
Adjective
  • Its dark terrain is constantly changing due to lava flows from Kilauea or Mauna Loa – two of the most active volcanoes in the world, according to the National Park Service website.
    Alia Beard Rau, USA Today, 10 June 2026
  • Some find the last scene ambiguous, multivalent; some dark; others comic.
    Literary Hub, Literary Hub, 10 June 2026
Adjective
  • Brunson is at his best when everything is at its worst, blessed with belief that seems at times desperate and determination that can feel almost manic.
    Dana O’Neil, CNN Money, 14 June 2026
  • All of the club’s worst seasons prior to 1965 took place from 1932 and before.
    Mac Cerullo, Boston Herald, 14 June 2026

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Cite this Entry

“Nefarious.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/nefarious. Accessed 15 Jun. 2026.

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