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 Back then, this information was a literal document, something that could be tangibly stored in a safe space and kept away from any nefarious or ill-intentioned parties. William Jones, USA Today, 3 June 2026 Be it getting hit by a car, taken by predators, or snatched up for nefarious reasons like being used for dog fights. Stephen Underwood, Hartford Courant, 2 June 2026 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 See All Example Sentences for nefarious
Recent Examples of Synonyms for nefarious
Adjective
  • It has not been confirmed whether The Legend of Zelda movie will be based on a single game from the franchise or inspired by the overall story of Link saving Princess Zelda and the land of Hyrule from the evil sorcerer Ganon.
    Christopher Rudolph, PEOPLE, 7 Dec. 2025
  • There are hints of nuclear incident, climate collapse, AI run amok — all filtered through the narrow perspective of a survivor’s diary written in a convent where evil nuns hold sway over the worthy and unworthy alike.
    Emma Alpern, Vulture, 2 Dec. 2025
Adjective
  • Their primary mission is to enforce immigration laws, prevent unlawful entry into the country and investigate smuggling or trafficking.
    Tiffani Jackson, Fort Worth Star-Telegram, 11 Dec. 2025
  • The Cup teams sued NASCAR in October 2024 on the grounds that the private company was an unlawful monopoly — one that used anti-competitive practices to strengthen itself and weaken the teams.
    Alex Zietlow, Charlotte Observer, 11 Dec. 2025
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
  • Beyond that coincidence, Coleman grew to appreciate Alexander as a multi-sport star – a standout hurdler in track and a tough defender/vicious dunker in basketball.
    Walter Villa, Miami Herald, 9 Dec. 2025
  • Takahashi’s story delights in throwing more and more wrenches in the works with a growing cast of chaotic supporting characters (like the vicious Shampoo and the blowhard Tatewaki Kuno), and the anime adapts their antics as pastel-toned slapstick.
    Kambole Campbell, Vulture, 9 Dec. 2025
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
  • But the true story behind it is a dark, sad and overall pretty confusing one.
    Nick Miller, New York Times, 17 June 2026
  • Trudeau embraced the Southern California vibes and wore a green T-shirt with black shorts and a pair of dark sunglasses.
    Tracy Wright, FOXNews.com, 16 June 2026
Adjective
  • The Canadian Whale Institute said Friday that efforts to find the whale have been unsuccessful and the search has been hampered by bad weather.
    Neal Riley, CBS News, 14 June 2026
  • This is for the fans who endured the three-worst seasons in Knicks history all inside of a five-year span.
    Kristian Winfield, New York Daily News, 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 17 Jun. 2026.

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